Glucagon-like peptide-1 (GLP-1) receptor agonists are medications used to improve blood sugar control in type 2 diabetes and to promote weight loss in obesity. They are currently all the rage, and they are no longer just being taken by people who are severely overweight. Many people today are jumping on the GLP-1 weight loss band-wagon. However, many people don’t realize the risks involved and the serious side effects that can happen if you are on these drugs like Ozempic, Wegovy, Mounjaro and otheres. Below is a comprehensive overview of all GLP-1 receptor agonists available in the U.S. (including current and discontinued drugs), organized by brand name and manufacturer. Each section details the medication’s brand/generic name and manufacturer, its status (available or discontinued), major side effects (with emphasis on serious risks and FDA warnings), and relevant U.S. legal actions (lawsuits or settlements) involving the drug or its manufacturer.
Ozempic® (semaglutide) – Novo Nordisk
Overview: Ozempic is a once-weekly injectable GLP-1 agonist approved in 2017 for type 2 diabetes. It lowers blood sugar and reduces the risk of major cardiovascular events in adults with type 2 diabetes and established heart disease. Semaglutide (the active ingredient) also promotes weight loss, though Ozempic’s official indication is diabetes management. Novo Nordisk markets semaglutide separately as Wegovy for obesity and weight loss.
Side Effects and FDA Warnings
According to the FDA, the most common side effects include nausea, vomiting, diarrhea, abdominal pain, and constipation are frequently reported with semaglutide and other GLP-1 agonists. These gastrointestinal (GI) effects are dose-dependent and often occur during dose escalation. Patients are advised to titrate doses gradually to improve tolerability. However, it’s the most serious side effects that are most concerning and the foundation of lawsuits filed against Novo Nordisk.
Serious risks from taking Ozempic
All GLP-1 agonists (including semaglutide) carry a boxed FDA warning about thyroid C-cell tumors observed in rodents. Ozempic is contraindicated in patients with a personal or family history of medullary thyroid carcinoma or MEN-2 (multiple endocrine neoplasia type 2). Notably, this class-wide warning applies to all long-acting GLP-1 RAs; short-acting agents like exenatide [Byetta] and lixisenatide [Adlyxin] were exempted, as they did not show this risk in rodents
- Gastroparesis (“Stomach Paralysis”): Ozempic slows gastric emptying, which in some cases can lead to symptoms resembling gastroparesis, such as severe nausea, vomiting, bloating, and abdominal discomfort.
- Pancreatitis: Inflammation of the pancreas presenting as severe abdominal pain that may require immediate medical attention.
- Thyroid C-Cell Tumors: There is a potential risk for thyroid tumors, including medullary thyroid carcinoma, as observed in animal studies.
- Acute Kidney Injury: Dehydration secondary to severe gastrointestinal symptoms can lead to kidney issues.
- Severe Gastrointestinal Issues: Beyond gastroparesis, symptoms such as intense nausea, vomiting, or diarrhea can occur, potentially leading to dehydration.
- Hypoglycemia: Especially when Ozempic is used in combination with other diabetes medications like insulin or sulfonylureas.
- Allergic Reactions: Serious hypersensitivity reactions, including anaphylaxis, though these are rare.
- Gallbladder Disease: There is an association with gallbladder-related issues, such as cholelithiasis (gallstones) and cholecystitis.
- Diabetic Retinopathy Complications: Some patients have experienced worsening of diabetic eye disease, so monitoring is advised if you have pre-existing retinopathy.
- Other warnings: Semaglutide can cause gallbladder disease (such as gallstones or cholecystitis), especially with significant weight loss or high doses
In trials, higher doses and longer use of GLP-1 RAs were associated with more gallbladder-related events. Ozempic’s label also contains a warning about diabetic retinopathy complications: initial studies (e.g. SUSTAIN-6) found an increased risk of diabetic retinopathy worsening in patients on Ozempic. As a result, Ozempic and Wegovy labels include precautions about potential vision changes. Patients with existing retinopathy should be monitored when starting therapy. Additionally, because semaglutide significantly slows gastric emptying, the FDA recently added a warning about the risk of aspiration under anesthesia – patients on Ozempic may have residual stomach contents and should discuss pre-surgery fasting guidelines with their doctors.
Comparative risk profile: Semaglutide is one of the most potent GLP-1 RAs, yielding greater HbA1c reduction and weight loss than many other meds. However, it also tends to cause higher rates of GI side effects compared to some peers. Head-to-head trials indicate that weekly semaglutide causes more nausea and vomiting than agents like dulaglutide or exenatide extended-release, though GI effects are generally transient and lead to low overall discontinuation rates (<10% in trials). Like other weekly injections, Ozempic can cause mild injection-site reactions, but these are less frequent than with exenatide weekly (Bydureon), which often causes small nodules under the skin.
Ozempic Lawsuits and Settlements
Ozempic’s manufacturer (Novo Nordisk) is currently facing a wave of product liability lawsuits concerning semaglutide.
Gastroparesis and GI Injury Litigation: In the last two years, numerous patients filed lawsuits alleging that Ozempic (and similar GLP-1 drugs) caused severe gastrointestinal injuries, notably gastroparesis (“stomach paralysis”) resulting in chronic nausea, vomiting, and in some cases intestinal blockage. These cases have been consolidated into a federal multidistrict litigation (MDL) in the U.S. (MDL No. 3082, In re GLP-1 RA Products Liability Litigation). As of late 2024, over 1,300 lawsuits were pending in this MDL against Novo Nordisk and co-defendant Eli Lilly. Plaintiffs claim the companies failed to warn adequately about the risk of gastroparesis and related serious GI side effects, which is true for almost any pharmaceutical drug with serious side effects. In one suit, for example, a patient alleges she developed persistent vomiting and was diagnosed with gastroparesis after only a few months on Ozempic. While they are great for weight loss, these are the risks that people take when taking Ozempic.
The lawsuits seek compensation for medical expenses, pain and suffering, and allege that Novo Nordisk’s aggressive marketing downplayed these risks while emphasizing weight loss benefits. The litigation is in early stages (discovery and pre-trial motions through 2024), and no settlements or verdicts have been reached yet. A court hearing to review scientific evidence on the drugs’ link to gastroparesis is scheduled for May 2025
Other legal actions: Novo Nordisk has also been involved in patent litigation over semaglutide. Notably, Novo faced a challenge from Mylan (Viatris) seeking to invalidate Ozempic’s semaglutide patent, but in October 2023 the U.S. Patent Trial and Appeal Board upheld the patent. Subsequently, in late 2024, Novo Nordisk and Mylan reached a settlement in their patent dispute (details of the settlement, including any agreed-upon generic entry date for semaglutide, were not publicly disclosed).
These patent negotiations do not involve safety claims but are significant for future generic competition. As of February 2025, no class-action settlement amounts or jury awards have been paid out in the Ozempic injury litigation – the cases remain ongoing in the courts.
Wegovy® (semaglutide) – Novo Nordisk
Overview: Wegovy is the brand name for semaglutide when used at higher doses for obesity treatment. Approved in 2021 for chronic weight management, it’s a once-weekly injection indicated for adults with obesity or overweight (with at least one weight-related comorbidity). Wegovy’s active ingredient and mechanism are the same as Ozempic’s, so its efficacy and side effect profile are very similar. The key difference is dosing: Wegovy is titrated up to 2.4 mg weekly (higher than Ozempic’s usual 2 mg max for diabetes) to achieve greater weight loss.
Side Effects and FDA Warnings
Common side effects: As with Ozempic, GI reactions (nausea, vomiting, diarrhea, abdominal discomfort, constipation) are extremely common with Wegovy. Due to the higher target dose for weight loss, a gradual 16-week dose escalation (starting at 0.25 mg/week up to 2.4 mg/week) is used to mitigate nausea
Still, many patients experience transient nausea or appetite loss as part of Wegovy’s satiety-enhancing effect. Other common effects can include headache, fatigue, and dyspepsia (indigestion).
Wegovy Serious risks and side effects
Wegovy carries the same boxed warning for thyroid C-cell tumors as Ozempic (contraindicated in patients with a history of medullary thyroid carcinoma or MEN-2)
- Delayed Gastric Emptying: Wegovy can slow the passage of food through the stomach, leading to symptoms similar to gastroparesis such as nausea, vomiting, and abdominal discomfort.
- Pancreatic Inflammation: There is a risk of developing pancreatitis, which typically presents as severe abdominal pain that may require urgent evaluation.
- Thyroid Concerns: Animal studies have raised concerns about the possibility of thyroid C-cell tumors, so caution is advised, especially if there’s a family history of thyroid issues.
- Kidney Issues: Significant gastrointestinal distress can lead to dehydration, which in turn might impair kidney function or cause acute kidney injury.
- Serious Gastrointestinal Reactions: In addition to delayed gastric emptying, patients might experience profound nausea, vomiting, or diarrhea, which can have serious consequences if not managed properly.
- Low Blood Sugar Episodes: When Wegovy is combined with other medications that lower blood sugar, there can be an increased risk of hypoglycemia.
- Allergic Responses: Although uncommon, some individuals may experience severe allergic reactions, including anaphylaxis.
- Biliary Complications: There is a potential for gallbladder issues, such as the formation of gallstones or inflammation of the gallbladder, particularly in predisposed individuals.
- Eye Health Concerns: For patients with diabetes, there might be a risk of worsening diabetic retinopathy, so monitoring eye health is important during treatment.
Acute pancreatitis is a known risk as well – any unexplained severe abdominal pain on Wegovy should prompt evaluation for pancreatitis. Rapid weight loss with Wegovy can predispose patients to gallbladder problems (gallstones or inflammation); clinical trials of liraglutide (a similar GLP-1 for weight loss) noted an increase in gallstone events, and GLP-1 class data indicate an elevated likelihood of biliary disorders with higher doses. Wegovy’s FDA label also includes the diabetic retinopathy warning (as semaglutide can transiently worsen diabetic eye disease in those with diabetes). Additionally, because Wegovy slows gastric emptying, the risk of gastroparesis is a concern (indeed, this is mechanistically how it promotes satiety). Patients with severe pre-existing gastroparesis should not use it
Ongoing investigations are examining whether GLP-1 drugs might have any link to mood changes; the FDA’s 2024 safety communication noted no proven causal link between semaglutide and suicidal ideation, but it continues to monitor this potential risk
Risk profile compared to other GLP-1s:
Semaglutide at obesity-dosing (Wegovy) achieves the greatest weight loss among current GLP-1 RAs, but higher doses can mean more side effects. GI side effects are dose-related; notably, semaglutide (Wegovy/Ozempic) tends to cause more nausea than weekly dulaglutide (Trulicity) or daily liraglutide (Saxenda/Victoza) in head-to-head comparisons. On the other hand, longer-acting formulations like Wegovy generally have fewer injection-site issues compared to agents like exenatide weekly. Overall, Wegovy’s safety profile mirrors Ozempic’s – the main difference is a higher incidence of gastrointestinal effects due to the higher dose required for weight loss.
Lawsuits and Settlements
Wegovy is involved in the same litigation as Ozempic, given that both are semaglutide made by Novo Nordisk. Patients who used Wegovy for weight loss and then suffered severe gastrointestinal injuries (such as chronic vomiting, gastroparesis, or intestinal blockage) have joined the consolidated MDL against Novo Nordisk. For example, one lawsuit filed in late 2024 involves a woman alleging that using Novo Nordisk’s Ozempic and Wegovy caused her “severe, chronic gastrointestinal injuries, including gastroparesis”. Her complaint (like others) asserts that Novo Nordisk knew or should have known about the risk of stomach paralysis and failed to warn patients, instead marketing the drugs as safe and effective for weight management. In December 2024, the Judicial Panel on Multidistrict Litigation expanded the scope of the federal GLP-1 lawsuits MDL to explicitly include claims from patients who used Saxenda (liraglutide for weight loss) as well. This indicates the MDL now encompasses most GLP-1 agonists used for obesity or diabetes, including Wegovy. No individual Wegovy-specific settlements have been reported to date; any resolution will likely occur as part of a global settlement or verdict covering multiple GLP-1 drugs. As of early 2025, Novo Nordisk has not paid any settlement in this matter and is defending the safety of Wegovy and Ozempic in court. Novo Nordisk did, however, reach a patent lawsuit settlement in October 2024 to fend off generic semaglutide competition (settling with Viatris/Mylan regarding Ozempic/Wegovy patents), but this was unrelated to patient injury claims.
Rybelsus® (semaglutide) – Novo Nordisk
Overview: Rybelsus is the first (and currently only) oral GLP-1 receptor agonist, containing semaglutide in tablet form. Approved in 2019 for type 2 diabetes, it’s taken once daily on an empty stomach
. Rybelsus offers an alternative for patients who prefer pills over injections, though the mechanism and side effect profile of the drug remain similar to injectable semaglutide.
Side Effects and FDA Warnings
- Common side effects: Oral semaglutide causes gastrointestinal side effects similar to the injectable form. Nausea is the most common adverse effect, especially during the initial weeks or when increasing the dose from 3 mg to 7 mg to 14 mg daily
. Other frequent effects include vomiting, diarrhea, abdominal pain, and decreased appetite. These effects are usually mild to moderate and tend to improve over time or with dose adjustments.
- Serious risks: Rybelsus carries the class boxed warning for thyroid C-cell tumors (like Ozempic/Wegovy) – patients with a history of MTC or MEN-2 should not use it
. Pancreatitis is a risk as well; patients are advised to seek medical attention for severe abdominal pain and discontinue if pancreatitis is confirmed
. Because Rybelsus is systemic semaglutide, albeit oral, it can potentially cause the same serious adverse events seen with injections: gallbladder issues (from rapid weight loss), allergic reactions, and kidney injury from dehydration (if severe vomiting/diarrhea occur)
. One distinction is that Rybelsus’ label emphasizes proper administration (taking with water and waiting 30 minutes before eating) to ensure absorption – improper use could lead to reduced efficacy or more variable GI effects.
- Risk profile notes: In trials, oral semaglutide’s overall safety was consistent with the GLP-1 class. Rates of GI side effects might be slightly lower than with the maximal injectable dose, since Rybelsus’ top dose (14 mg daily) is roughly equivalent to a medium dose of Ozempic. However, because it’s taken daily, some patients experience continuous mild nausea rather than the weekly “peak” effects of an injection. Efficacy in glucose lowering is a bit less than injectable semaglutide, but so are some side effects
. Importantly, Rybelsus still requires the same precautions: it is not recommended in patients with severe gastrointestinal disease (like significant gastroparesis or IBD)
and should be used with caution in those with diabetic retinopathy (monitor for changes in vision).
Lawsuits and Settlements
Rybelsus, being a semaglutide product by Novo Nordisk, is indirectly swept into the ongoing GLP-1 litigation, although most publicized cases have involved the injectable forms. Some plaintiffs in the MDL have used broad language to include “similar GLP-1 drugs” beyond Ozempic, which would cover Rybelsus if a patient on the oral form experienced comparable injuries
. However, as of now, there have been no high-profile lawsuits solely focused on Rybelsus. The gastrointestinal injury lawsuits against Novo Nordisk primarily center on Ozempic and Wegovy (likely because these have been more widely used and at higher doses). Novo Nordisk’s liability defense for Rybelsus would be the same as for its injectables – that the company provided adequate warnings and that a definitive causal link between GLP-1 drugs and long-term gastroparesis has not been proven. No settlements or judgments specific to Rybelsus have been reported. In summary, no distinct legal actions target Rybelsus alone in the past two years, aside from its inclusion in class-wide litigation against Novo Nordisk regarding GLP-1 agonists generally.
Victoza® (liraglutide) – Novo Nordisk (Available)
Overview: Victoza is a once-daily injectable GLP-1 agonist (liraglutide) approved in 2010 for type 2 diabetes. It was the second GLP-1 RA on the U.S. market (after exenatide) and gained popularity for its strong glucose-lowering effect and proven cardiovascular benefit. Victoza is also approved to reduce the risk of major adverse cardiac events in adults with type 2 diabetes and established cardiovascular disease
. Liraglutide is the same molecule later repurposed at higher dose for weight loss as Saxenda.
Side Effects and FDA Warnings
- Common side effects: Gastrointestinal issues are very common with Victoza. Nausea is the hallmark side effect, especially upon treatment initiation; up to 20–40% of patients may experience nausea in early weeks. Other common effects include vomiting, diarrhea, or constipation, and these often subside with continued use. Injection-site reactions (redness or rash) can occur but are generally mild. Liraglutide, being shorter-acting than weekly injections, can cause some patients to feel transient nausea each day after the shot, but this can be managed by taking the dose at a consistent time and not overeating.
- Serious risks: Thyroid tumor risk – Liraglutide carries an FDA boxed warning for thyroid C-cell tumors (observed in rodent studies). Victoza is contraindicated in patients with a personal or family history of medullary thyroid carcinoma or MEN-2 syndromes
. Pancreatitis – Postmarketing reports linked Victoza (and other GLP-1 RAs) to pancreatitis. Patients should discontinue Victoza if pancreatitis is suspected or confirmed. Gallbladder disease – Rapid weight loss or the drug itself can precipitate gallstone formation; liraglutide’s weight-loss effect in diabetics is more modest than in obesity treatment, but cases of cholecystitis (gallbladder inflammation) have been noted. Kidney injury – Victoza can cause dehydration from nausea/vomiting, which in turn has led to reports of acute kidney injury in susceptible individuals (especially those with prior kidney disease or on NSAIDs/diuretics). The FDA has cautioned about monitoring renal function if severe GI reactions occur.
- Comparative profile: Liraglutide is a potent GLP-1 agonist but must be injected daily. Compared to weekly GLP-1 agents (dulaglutide, semaglutide), liraglutide tends to cause slightly more frequent GI side effects (due to daily dosing) but each episode may be less intense than the peaks from weekly doses
. Head-to-head, semaglutide 1.0 mg weekly showed greater A1c reduction and weight loss than liraglutide 1.8 mg daily, but also a bit more nausea in trials
. Liraglutide’s side effect profile is otherwise typical for the class; notably, it did not show the diabetic retinopathy signal that semaglutide did. All GLP-1 RAs, Victoza included, have a low intrinsic risk of hypoglycemia (since they only increase insulin in a glucose-dependent manner)
, but hypoglycemia can occur when combined with insulin or sulfonylureas, so those doses may need reduction.
Lawsuits and Settlements
Pancreatic Cancer Litigation: Victoza was one of the drugs named in a large multi-district litigation (MDL No. 2452) concerning incretin-based therapies and pancreatic cancer. Starting around 2012–2013, hundreds of patients who had taken Victoza (as well as other GLP-1 drugs like Byetta and DPP-4 inhibitors like Januvia) filed lawsuits alleging these medications caused pancreatitis and, in some cases, pancreatic cancer
. Plaintiffs claimed Novo Nordisk and other manufacturers failed to warn about these cancer risks
. The FDA and European Medicines Agency investigated this issue in 2013 and found no conclusive evidence of causation, although they could not rule out a small risk
. The litigation saw many twists – in 2015, a federal judge (Judge Anthony Battaglia) dismissed the consolidated cases under the doctrine of federal preemption (citing the FDA’s findings)
. That dismissal was reversed on appeal in 2018, allowing the suits to proceed. However, after further expert discovery, the judge again ruled in favor of the drug companies in 2021, finding insufficient evidence that Victoza or the other drugs caused pancreatic cancer
. By late 2022, the incretin mimetic MDL was closed without any settlement or finding of liability
. In short, Novo Nordisk successfully defended Victoza in that litigation – no damages were paid to plaintiffs, as the court concluded the evidence did not prove Victoza causes pancreatic cancer.
Current lawsuits: Victoza is now an older product, and recent legal attention has shifted to newer drugs. Victoza’s maker, Novo Nordisk, is nonetheless indirectly involved in the ongoing 2023–2024 GLP-1 lawsuits (for gastroparesis) because those suits target the company and its GLP-1 franchise as a whole. Most claimants in MDL-3082 took Ozempic/Wegovy, but a few may have used Victoza or transitioned between drugs. The MDL master complaint consolidating GLP-1 injury claims would cover Victoza if a plaintiff alleged injuries from it
. So far, Novo Nordisk has not faced any separate, Victoza-specific new lawsuits in the last two years. No settlements involving Victoza have been publicly reported in this period.
Saxenda® (liraglutide) – Novo Nordisk (Available)
Overview: Saxenda is the brand name for liraglutide 3.0 mg, approved in 2014 for chronic weight management. It is essentially the same drug as Victoza but given at a higher daily dose for obesity treatment. Saxenda is indicated for adults with a BMI ≥30 (or ≥27 with weight-related comorbidities) as an adjunct to diet and exercise. Patients titrate Saxenda from 0.6 mg up to 3 mg daily over several weeks
. Saxenda was the first GLP-1 agonist approved for weight loss and has been widely used until newer agents like semaglutide came along.
Side Effects and FDA Warnings
- Common side effects: Due to its higher dose, nausea is very frequent with Saxenda, especially during dose escalation. In clinical trials, a majority of patients reported some GI symptom. Nausea, vomiting, diarrhea, and constipation are the top complaints. Many patients also experience loss of appetite (which is partly the intended effect). Other side effects can include headache, dizziness, abdominal bloating, and injection site reactions. Because Saxenda is daily, patients often find the side effects manageable by adjusting meal sizes and timing (to avoid eating too much when the medication is active).
- Serious risks: Saxenda carries the same boxed warning about thyroid C-cell tumors as Victoza (liraglutide’s diabetes dose)
. It should not be used in patients with a personal/family history of medullary thyroid carcinoma or MEN-2 syndrome. Pancreatitis has been observed in a small fraction of patients on Saxenda; any severe abdominal pain should prompt discontinuation and evaluation
. Gallbladder disease is a notable risk in weight-loss use: Saxenda’s prescribing information warns about cholelithiasis and cholecystitis. In the Phase 3 trials, more Saxenda-treated patients developed gallstones than those on placebo, likely due to the weight loss-induced changes in bile composition. Some cases required gallbladder surgery. Renal impairment can occur secondary to severe vomiting or dehydration. Depression or suicidal ideation: A slight increase in reports of depression, mood changes, and suicidal thoughts was noted in weight-loss trials (though causality is unclear). Patients are advised to report mood changes; liraglutide (for weight loss) has a warning in Europe about this risk, and the FDA is evaluating it class-wide
.
- Risk profile compared to other GLP-1s: At 3.0 mg daily, liraglutide causes significant weight loss but at the cost of more frequent side effects than lower doses. In weight management trials, dropout rates due to adverse events were higher with Saxenda than placebo. Compared to weekly semaglutide 2.4 mg (Wegovy), Saxenda is less effective for weight loss (around 5–8% body weight reduction on average vs. ~15% with semaglutide) but also generally has fewer systemic side effects because semaglutide’s potency is greater. Saxenda’s GI side effect incidence is high, but these effects are typically mild to moderate and occur early in therapy. It does not appear to cause the retinopathy issue observed with semaglutide. In summary, Saxenda’s safety profile is very similar to Victoza’s, just with side effects occurring more often due to the higher dose used for obesity.
Lawsuits and Settlements
While Saxenda had been on the market for several years with no major controversy, it has recently become part of the ongoing GLP-1 litigation related to gastrointestinal injuries. In December 2024, the panel overseeing the federal GLP-1 lawsuits decided to include Saxenda-related claims in the consolidated MDL
. This means that individuals who used Saxenda and developed conditions like gastroparesis or severe GI complications can have their cases heard alongside those of Ozempic/Wegovy users. The decision to add Saxenda was likely prompted by reports of similar stomach-related injuries among Saxenda patients and the fact that Novo Nordisk manufactures Saxenda as well
. Both plaintiffs’ lawyers and Novo Nordisk supported including Saxenda in the MDL, indicating recognition that the drugs have comparable risk profiles for the injuries alleged
.
Aside from its inclusion in the MDL, no separate high-profile lawsuits specific to Saxenda alone have been publicized in the last two years. Earlier in its life, Saxenda did not face the pancreatic cancer lawsuits that Victoza did (since those were initiated before Saxenda’s approval). If any Saxenda users experienced pancreatitis or gallbladder issues, those were handled as individual adverse event cases rather than large-scale litigation. As of early 2025, Novo Nordisk has not reached any settlement specifically for Saxenda. Any future legal outcomes for Saxenda will likely be tied to the broader GLP-1 cases. No settlement amounts or resolutions have been announced yet in the MDL that now includes Saxenda, and Novo Nordisk is contesting the claims.
Trulicity® (dulaglutide) – Eli Lilly (Available)
Overview: Trulicity is a once-weekly injectable GLP-1 agonist (dulaglutide) made by Eli Lilly, approved in 2014 for type 2 diabetes. It comes as a ready-to-use pen and has been a popular choice due to its convenience (no mixing or complex setup)
. Dulaglutide has demonstrated cardiovascular benefits in patients with diabetes and high CV risk, and more recently higher doses of Trulicity have been studied for greater glucose control.
Side Effects and FDA Warnings
- Common side effects: Like all GLP-1 RAs, dulaglutide commonly causes gastrointestinal symptoms. Nausea is the most reported side effect, especially after the first few injections. Other common effects include vomiting, diarrhea, abdominal pain, and sometimes decreased appetite. These symptoms are often transient and tend to improve after a few doses as the body adjusts. Some patients experience fatigue or slight dizziness on the day of injection. Injection-site reactions (redness or itching) can occur but are generally mild; Trulicity’s single-use pen has a hidden needle designed to minimize discomfort.
- Serious risks: Thyroid C-cell tumor warning – Trulicity has the class boxed warning for thyroid C-cell tumors (observed in rodent studies)
. It should not be used in patients with a history of medullary thyroid carcinoma or MEN-2. Pancreatitis – Dulaglutide has been associated with pancreatitis in rare cases. Any unexplained, severe abdominal pain warrants stopping the medication and evaluating for pancreatitis
. Renal impairment – There have been postmarketing reports of acute kidney injury and worsening renal function in patients who had severe vomiting or diarrhea from GLP-1 agonists. Caution is advised in those with moderate to severe kidney disease, and maintaining hydration is important. Hypersensitivity – Though uncommon, serious allergic reactions including angioedema have been reported with GLP-1 RAs; if this occurs, Trulicity should be discontinued. Dulaglutide does not cross the blood-brain barrier significantly, and unlike some other peptides, it hasn’t been linked strongly to central effects, but ongoing monitoring for any signal of retinopathy changes or mood changes is part of pharmacovigilance.
- Risk profile notes: In comparative trials, dulaglutide tends to cause slightly less nausea than semaglutide. For example, studies have found that high-dose weekly semaglutide had higher rates of GI side effects than dulaglutide at standard doses
. Dulaglutide’s efficacy in lowering HbA1c is high (especially at the newer max dose 4.5 mg), and it also causes weight loss, though a bit less than semaglutide. Injection site nodules are less of an issue with dulaglutide than with exenatide XR, because dulaglutide is a soluble protein without microspheres. Like others, discontinuation due to side effects was under 10% in trials
. Dulaglutide shares the cardioprotective indication (it reduced cardiovascular events in the REWIND trial), and no unique side-effect beyond the class effects has emerged. One minor distinction: dulaglutide is a larger molecule (a GLP-1 analog fused to an antibody fragment), and thus it has lower immunogenicity issues – anti-drug antibodies are rarer with Trulicity than with exenatide, for instance
.
Lawsuits and Settlements
Trulicity (dulaglutide) has not been the focus of major individual lawsuits in the past two years, but Eli Lilly, its manufacturer, is a key defendant in the recent GLP-1 class-action litigation. The multidistrict litigation over GLP-1 agonists and gastroparesis includes Lilly’s drugs as well – notably Mounjaro (tirzepatide) and by extension Trulicity, since plaintiffs refer to “GLP-1 receptor agonists” broadly
. Some lawsuits explicitly name Mounjaro, Ozempic, and Wegovy, but any Trulicity user who experienced similar GI injuries could also be part of the consolidated action. There have not been widely reported cases of Trulicity causing severe gastric paralysis in the news media, perhaps because its use is primarily diabetes (and at lower doses than weight-loss drugs). Nonetheless, Lilly is co-defending the GI injury claims. As of February 2025, no specific settlements or verdicts involving Trulicity alone have been reported.
In earlier years, Trulicity was tangentially involved in the same incretin-pancreatic cancer litigation that affected Victoza and Byetta. However, Trulicity was approved in 2014, and the bulk of those lawsuits predated its availability. If any plaintiffs later added Trulicity (for example, if they developed pancreatic cancer after using multiple GLP-1 drugs), those would have been folded into the MDL that, as noted, was dismissed in favor of the manufacturers by 2021
. No settlements were paid in that litigation.
Lastly, it’s worth noting that Eli Lilly reached a settlement with Novo Nordisk in 2023 in a dispute where Novo alleged Lilly improperly used its trademarked marketing phrases for GLP-1 drugs – a minor legal quarrel in the weight-loss drug marketing battle
. This did not involve Trulicity’s safety, but illustrates the competitive and legal landscape between manufacturers. Overall, Trulicity’s manufacturer Lilly is actively engaged in legal defense related to GLP-1 drugs, but Trulicity itself hasn’t seen unique lawsuit headlines in the last two years. No settlement payouts specific to Trulicity have occurred.
Mounjaro® (tirzepatide) – Eli Lilly (Available)
Overview: Mounjaro is a once-weekly injection approved in 2022 for type 2 diabetes. It is a dual GLP-1/GIP receptor agonist (activating both the GLP-1 and glucose-dependent insulinotropic polypeptide receptors)
. While not a pure GLP-1 agonist, its strong GLP-1 activity places it in the same therapeutic arena. Mounjaro has shown remarkable efficacy in lowering blood sugar and body weight, and Eli Lilly has also received FDA approval (in late 2023) for the same drug (tirzepatide) under the brand Zepbound for obesity. Mounjaro’s dosing ranges from 2.5 mg up to 15 mg weekly
.
Side Effects and FDA Warnings
- Common side effects: Tirzepatide’s side effect profile overlaps with GLP-1 agonists. Nausea, vomiting, and diarrhea are very common, especially during dose escalation. Some patients also report abdominal pain or indigestion. Because tirzepatide also stimulates GIP receptors, there was speculation whether this would reduce GI side effects, but clinical trials showed similar GI tolerability issues as seen with GLP-1 RAs (though possibly not worse). Other common effects include decreased appetite, dizziness, and constipation.
- Serious risks: Thyroid tumors – Mounjaro carries a boxed warning about thyroid C-cell tumors, just like GLP-1 agonists, because rodent studies with tirzepatide showed thyroid tumor development
. It is contraindicated in patients with MTC or MEN-2 history. Pancreatitis – Cases of pancreatitis were observed in tirzepatide trials as well; the warning for acute pancreatitis is present, and patients with a history of pancreatitis were excluded from trials as a precaution. Gastroparesis – Given tirzepatide’s powerful effect on slowing gastric emptying, it can cause significant delays in digestion; it is not recommended in people with symptomatic gastroparesis. Indeed, early post-marketing reports have linked Mounjaro to severe gastrointestinal motility disorders (similar to GLP-1 drugs). Hypoglycemia – Tirzepatide alone has low risk of severe hypoglycemia, but when combined with insulin or sulfonylureas, the risk is higher due to improved glycemic levels; dose adjustments of those agents are advised. Retinopathy and other risks – No specific retinopathy signal unique to tirzepatide has been flagged yet, but as with any drug causing rapid glucose improvements, monitoring in patients with diabetic eye disease is prudent. Also, like Saxenda/Wegovy, regulators are watching for any mood or suicidal ideation signals; none were clearly seen in trials, but the class evaluation by FDA in 2024 covers tirzepatide too
.
- Comparative profile: Tirzepatide (Mounjaro) often induces more weight loss than single-action GLP-1 agonists – in trials it led to weight reductions around 20% at high doses, versus ~15% with semaglutide
. With that greater efficacy, GI side effects can be pronounced but were still in a similar range as semaglutide’s in head-to-head comparisons. Some data suggested that by the highest doses (15 mg), nausea rates might be slightly higher than with 1 mg semaglutide, but overall tolerability was good enough that discontinuation rates remained under 10% in studies. One notable difference: tirzepatide can cause more appetite suppression and food aversion (patients sometimes describe an altered taste for food), which is part of how it works for weight loss. As a result, adequate nutrient intake should be monitored during rapid weight loss. Otherwise, its safety profile aligns with what is expected from potent incretin-based therapies.
Lawsuits and Settlements
Despite being relatively new, Mounjaro (tirzepatide) has quickly become entangled in legal issues similar to those of Ozempic. Product liability lawsuits: Beginning in mid-to-late 2023, some patients who took Mounjaro for diabetes or off-label for weight loss have filed lawsuits claiming it caused them severe gastrointestinal injuries (such as persistent vomiting, gastroparesis, and stomach pain). These lawsuits mirror the Ozempic cases and have been rolled into the same federal MDL (often referred to as the “Ozempic” or GLP-1 MDL). Court filings explicitly list Mounjaro alongside Ozempic and Wegovy as drugs of concern
. By late 2024, the consolidated litigation (MDL-3082) included Mounjaro as one of the implicated medications in causing stomach paralysis and related GI complications
. Eli Lilly, therefore, is a co-defendant with Novo Nordisk in this MDL. As of February 2025, these cases are still in pre-trial phases; no settlement has been reached. However, with over a thousand cases pending and potentially many more to come
, there is speculation that a global settlement could be negotiated in the future if evidence mounts linking these drugs to the alleged injuries.
Aside from patient lawsuits, there have been other legal developments involving tirzepatide. In October 2023, the FDA approved Zepbound (the obesity-specific brand of tirzepatide), and around that time Lilly and Novo Nordisk were known to be fiercely competing. Novo Nordisk accused Lilly of recruiting social media influencers to promote Mounjaro for weight loss in a way that allegedly infringed Novo’s trademarks (such as using phrases associated with Novo’s products). This led to a lawsuit that was settled in 2023, with Lilly agreeing to modify its marketing practices
. While not directly about Mounjaro’s safety, it highlights the high-stakes environment for these medications.
In summary, active U.S. lawsuits involving Mounjaro are primarily the personal injury cases consolidated in the GLP-1 MDL. No specific payout or settlement figures exist yet for Mounjaro cases, and Lilly has publicly stated its intention to vigorously defend the safety of its drug. There have been no recalls of Mounjaro, and the FDA has not issued any specific safety warning uniquely for tirzepatide beyond the class warnings.
Zepbound® (tirzepatide) – Eli Lilly (Available)
Overview: Zepbound is essentially the same medication as Mounjaro (tirzepatide), but branded and indicated for chronic weight management. It was approved by the FDA in late 2023 specifically for obesity treatment
. Zepbound uses the same dosing regimen as Mounjaro (2.5 mg up to 15 mg weekly)
. The creation of a separate brand for obesity is similar to Victoza vs Saxenda. Because Zepbound only just launched, it shares its safety information with Mounjaro.
Side Effects and FDA Warnings
- Common side effects: Zepbound’s side effects are identical to Mounjaro’s (tirzepatide). Nausea is extremely common, affecting a large portion of patients during dose escalation. Vomiting, diarrhea, and constipation are also frequent. Patients on weight-loss doses often report appetite suppression (desired) but also sometimes food aversions or changes in taste. Other common effects include fatigue, dizziness, and abdominal discomfort. As with other GLP-1 agents used for weight loss, a slow titration schedule (over ~4 months) is mandated to mitigate GI symptoms
.
- Serious risks: Zepbound carries the boxed warning for thyroid C-cell tumors seen in tirzepatide and GLP-1 RA class labeling
. It is contraindicated in patients at risk for such tumors. Pancreatitis risk exists (though rare), and any signs of pancreatitis should prompt discontinuation. Gallbladder issues may occur due to rapid weight loss – gallstones can develop when weight is shed quickly; patients are advised to be aware of symptoms like upper abdominal pain or jaundice. GI obstruction or paralysis: Because tirzepatide so effectively slows gastric emptying, there is a risk of causing or exacerbating gastroparesis. In those with severe GI motility disorders, Zepbound should be avoided
. As of its approval, the FDA had the ongoing evaluation of suicidal ideation reports for the class; no specific warning is on Zepbound’s label yet, but healthcare providers are informed to monitor mood and cognition as a precaution
.
- Risk profile compared to other weight-loss meds: Tirzepatide (Zepbound) has shown greater average weight loss than semaglutide (Wegovy) in clinical trials
. Consequently, it may also have a higher incidence of certain side effects at the highest dose. However, overall tolerability in head-to-head comparisons was fairly similar. One advantage is that tirzepatide’s GIP agonism might theoretically counter some of the GLP-1–induced nausea (some studies hypothesize GIP co-agonism could reduce nausea), but in practice patients still experience substantial GI symptoms during titration. By contrast, non-GLP-1 weight-loss drugs (like phentermine/topiramate or bupropion/naltrexone) have a different side effect spectrum (more CNS effects, less GI), so patients who cannot tolerate GLP-1-related nausea sometimes consider those alternatives.
Lawsuits and Settlements
Given that Zepbound was only approved in late 2023, it hasn’t had time to generate its “own” lawsuits; however, any tirzepatide-related litigation would encompass Zepbound since it’s the same compound as Mounjaro. The existing GLP-1 MDL includes tirzepatide cases – some patients suing Eli Lilly may have been prescribed tirzepatide for weight loss (even before Zepbound’s formal approval, many doctors prescribed Mounjaro off-label for obesity). Those cases are now simply attributed to tirzepatide regardless of brand. As of early 2025, no specific legal actions targeting Zepbound by name have been reported. We can expect that any person who suffers an alleged injury from Zepbound will fold into the ongoing tirzepatide/Ozempic litigation.
No settlements or court judgments involve Zepbound specifically, given its recent debut. Eli Lilly’s legal team for tirzepatide will handle Zepbound issues identically to Mounjaro. It’s also worth noting that, to avoid potential patent issues or naming confusion, Lilly’s launch of Zepbound came with a careful strategy; however, no patent lawsuits or marketing lawsuits have centered on Zepbound to date (the earlier trademark scuffle with Novo Nordisk was in the context of Mounjaro marketing).
In summary, Zepbound has the same legal outlook as Mounjaro: it is part of the large-scale GLP-1 lawsuits alleging failure to warn about severe GI side effects, and it has no unique settlements or litigation history outside of that. Patients and prescribers should stay tuned as the broader cases progress or if any safety communications arise specifically mentioning obesity use.
Byetta® (exenatide) – AstraZeneca (Discontinued)
Overview: Byetta is a twice-daily injectable GLP-1 agonist (exenatide) originally developed by Amylin Pharmaceuticals and Eli Lilly, later marketed by AstraZeneca. Approved in 2005, it was the first GLP-1 agonist on the market. Byetta is a shorter-acting agent given before morning and evening meals to help control postprandial blood sugar spikes in type 2 diabetes. In recent years, Byetta has fallen out of favor and is no longer marketed in the U.S. (it was not widely available in the U.S. in recent years and was discontinued in other markets by 2024)
. AstraZeneca has ceased promotion of Byetta in the U.S. as newer weekly GLP-1 drugs have supplanted it.
Side Effects and FDA Warnings
- Common side effects: Byetta’s side effect profile heavily features gastrointestinal symptoms. Nausea was very prevalent in trials (up to ~40% of users initially). Because it’s given twice a day, patients often experience queasiness after injections, especially in the first month. Vomiting and diarrhea can also occur. Byetta can cause weight loss (often a welcome side effect in diabetes) due to reduced appetite and these GI effects. Other common adverse effects include dizziness, headache, and acid reflux.
- Serious risks: Pancreatitis – Exenatide was associated with early reports of acute pancreatitis. In 2007 and 2008, the FDA issued alerts after receiving numerous pancreatitis cases (some hemorrhagic or necrotizing) in Byetta users. The label was updated to include warnings about pancreatitis, advising discontinuation if it’s suspected. Kidney injury – There were also FDA warnings in 2009 about altered kidney function: some Byetta patients had reported acute renal failure or insufficiency, likely secondary to severe dehydration from vomiting or due to other factors
. Caution was recommended in patients with moderate renal impairment, and Byetta is contraindicated in severe renal impairment. Hypoglycemia – Byetta by itself has low hypoglycemia risk, but when added to a sulfonylurea, the combination could cause significant low blood sugars; dose adjustments of the sulfonylurea were advised. Thyroid tumors – Notably, Byetta (short-acting exenatide) did not carry the thyroid C-cell tumor boxed warning that longer-acting GLP-1s do
. This is because rodent studies for exenatide did not show the same thyroid C-cell changes as seen with drugs like liraglutide. Immunogenicity – Exenatide, being an exendin-4 analog (from Gila monster venom originally), can provoke anti-drug antibody formation. A significant fraction of patients develop antibodies to exenatide; in most cases this doesn’t cause problems, but in some it may reduce efficacy or (very rarely) cause allergic reactions.
- Risk profile notes: Byetta’s twice-daily dosing often led to higher frequency of GI upset compared to once-weekly formulations
. However, each dose is smaller, so the severity of nausea per episode might be less than what some experience at peak concentrations of weekly drugs. Head-to-head trials found that long-acting GLP-1 RAs (like liraglutide or exenatide weekly) had superior HbA1c reduction and less frequent nausea than Byetta, which contributed to Byetta’s decline in use
. A positive aspect of Byetta was that it had a short duration – if side effects occurred, they would wear off relatively quickly. Byetta was also weight-loss favorable and had a long safety record (over a decade of use) aside from the pancreatitis concern that emerged. It required patient commitment to two injections a day, which in an era of weekly options became a drawback.
Lawsuits and Settlements
Byetta was a central drug in earlier lawsuits concerning pancreatitis and pancreatic cancer. Along with Januvia (a DPP-4 inhibitor), Byetta was one of the incretin-based therapies targeted by plaintiffs who developed pancreatic cancer. Numerous Byetta lawsuits were filed, many consolidated into the federal MDL No. 2452 (Incretin Mimetics Products Liability Litigation) in the Southern District of California
. The plaintiffs alleged that Byetta’s manufacturers (Amylin and later Bristol-Myers Squibb/AstraZeneca) failed to warn about the risk of pancreatitis and pancreatic cancer
. They claimed Byetta was a defective drug that caused “unreasonable and dangerous” side effects and that the companies concealed these risks
. Over 1,000 cases were part of this litigation
.
As detailed in the Victoza section, this MDL saw the claims dismissed in 2015 on preemption grounds, reinstated on appeal, and then ultimately dismissed again in 2021 for lack of sufficient evidence of causation
. For Byetta, this means that the major pancreatic cancer lawsuits concluded without any payout to plaintiffs. In late 2022 the MDL closed, essentially a win for the manufacturers
. It’s worth noting that no settlement was reached – the cases were dismissed by the judge, a decision that effectively absolved the companies after years of legal battles. Some plaintiffs attempted state court actions, but none have resulted in a jury verdict against Byetta’s makers as of today.
In the last two years, the attention has shifted to newer GLP-1 drugs; thus, Byetta is not a focus of current lawsuits about gastroparesis (most of those involve weekly newer agents). Since Byetta has been discontinued in the U.S. and has a diminishing user base, we haven’t seen new injury claims for it. The legal legacy of Byetta lies in the resolved pancreatic cases. No recent settlements or lawsuits (2023–2025) involve Byetta specifically. AstraZeneca (which had acquired Amylin’s GLP-1 portfolio) has moved on to other products, and Byetta’s chapter in U.S. litigation is largely closed.
Bydureon® / Bydureon BCise® (exenatide extended-release) – AstraZeneca (Discontinued)
Overview: Bydureon is the long-acting, once-weekly formulation of exenatide. It was initially approved in 2012 (after Byetta) and came in two forms: a powder for suspension (injected via a vial/syringe or pen that required mixing) and later the Bydureon BCise autoinjector. Bydureon delivers exenatide encapsulated in microspheres for slow release. AstraZeneca marketed Bydureon after acquiring Amylin. Bydureon was discontinued in the U.S. as of March 2021 as a business decision (due to declining demand, not due to safety issues)
.
Side Effects and FDA Warnings
- Common side effects: Bydureon, being exenatide, shares many side effects with Byetta, but with some differences. Nausea was common, but interestingly, weekly exenatide tends to cause less frequent nausea than twice-daily exenatide because of slower, steady drug release
. Many patients still experience nausea, especially in the first 2 months, but often it is milder or more tolerable than with Byetta. Diarrhea, constipation, and vomiting are also reported. A distinctive side effect of Bydureon is injection site reactions and nodules – because the medication is injected as microspheres under the skin, patients often develop small, firm lumps at the injection site. These nodules can last several weeks as the microspheres dissolve, but they are generally not serious and tend to be painless
. Some patients might have redness or itching at the injection site.
- Serious risks: Thyroid tumor warning – Extended-release exenatide (Bydureon) did end up with the thyroid C-cell tumor boxed warning on its label. Although Byetta didn’t have that warning, the longer exposure from Bydureon led regulators to err on the side of caution. Thus, Bydureon was contraindicated in patients with medullary thyroid carcinoma history or MEN-2 (similar to others in its class)
. Pancreatitis – As with Byetta, pancreatitis has been observed with Bydureon. The risk and warning are class-wide: any signs of pancreatitis require stopping the drug
. Injection-site abscess or granuloma: In rare cases, the injection site nodules from Bydureon could become infected or form persistent granulomas. There were a few case reports of needing minor procedures to remove such lumps. Renal considerations – Since it’s the same exenatide molecule, Bydureon was not recommended in patients with severe renal impairment either.
- Risk profile notes: Bydureon’s GI side effect frequency is lower than that of shorter-acting GLP-1 RAs. Notably, in head-to-head trials, patients on exenatide weekly had less nausea than those on liraglutide daily or exenatide BID
. However, Bydureon’s trade-off was injection site lumps, which were a known benign issue but sometimes cosmetically concerning. Immunogenicity was a bit higher with Bydureon than Byetta (more patients developed anti-exenatide antibodies)
, but these antibodies generally didn’t cause adverse events, except they might reduce how well the drug worked in a small subset of patients. Bydureon provided steadier glucose control over the week and improved convenience, which was a safety benefit in terms of adherence (fewer missed doses than a BID regimen). All other serious side effects (pancreatitis, etc.) were similar to Byetta’s profile. No new unique toxicity was identified for Bydureon during its time on the market.
Lawsuits and Settlements
Bydureon was implicated in many of the same legal actions as Byetta. In the pancreatic cancer lawsuits of the 2010s, exenatide users were a major group – and that includes those on Bydureon. In fact, some plaintiffs specifically cited Bydureon, especially if they developed problems after 2012 when Bydureon became available. The consolidated MDL for incretin mimetics (MDL-2452) covered “exenatide products,” which would include both Byetta and Bydureon, and the defendant list included Amylin and Eli Lilly (original co-marketers) and later AstraZeneca
. The allegations (failure to warn about pancreatitis/pancreatic cancer) were essentially identical for Bydureon as for Byetta. Therefore, when Judge Battaglia dismissed those cases (and later re-dismissed them after appeal) for lack of evidence, that outcome applied to Bydureon-related claims as well
. No settlement was paid out for Bydureon; the cases ended in the manufacturers’ favor.
In the last couple of years, no new lawsuits centered on Bydureon have arisen. By 2021, the product was pulled from the U.S. market
, largely ending its exposure to new liability. It’s worth noting that around the time of discontinuation, AstraZeneca stated it was for business reasons, not safety
– Bydureon had been eclipsed by newer drugs like Trulicity and Ozempic. There haven’t been any publicized product liability suits specific to Bydureon’s known issues (like injection site nodules) – likely because those were not the kind of harm that typically leads to litigation (they were known and minor).
To sum up, Bydureon’s legal history is tied to the class-action pancreatic cancer litigation (which concluded with no plaintiff victories). Since discontinuation, AstraZeneca faces no ongoing lawsuits over Bydureon. No settlements were paid for Bydureon apart from a very small number of individual cases that might have been quietly settled out of court (none publicly reported). The major MDL saw Bydureon’s claims dismissed alongside Byetta’s.
Adlyxin® (lixisenatide) – Sanofi (Discontinued)
Overview: Adlyxin (known as Lyxumia abroad) is a once-daily GLP-1 agonist (lixisenatide) that was approved in the U.S. in 2016 for type 2 diabetes. It is a short-acting GLP-1 RA, similar in dosing to Byetta (injected once daily within one hour before the first meal of the day). Adlyxin had a relatively modest glucose-lowering effect focused on post-meal sugars. It was discontinued in the U.S. as of January 1, 2023 for commercial reasons, not due to any new safety concern
.
Side Effects and FDA Warnings
- Common side effects: Lixisenatide’s side effects mirror those of other short-acting GLP-1 agonists. Nausea is the most common, especially when first starting. Vomiting and diarrhea are also reported, though often mild. Patients might experience headache, dizziness, or injection site reactions (small redness or itching). Because Adlyxin was typically taken before breakfast, some patients reported that it mainly affected their appetite in the morning and wore off by later in the day. As with others, gradual dose escalation (starting from 10 µg to 20 µg daily) was recommended to reduce GI upset.
- Serious risks: Thyroid tumors – Notably, like Byetta, Adlyxin did not carry a boxed warning for thyroid C-cell tumors
. There was no signal of thyroid neoplasia in rodent studies for lixisenatide, distinguishing it from the longer-acting agents. Pancreatitis – Lixisenatide’s label included warnings for pancreatitis. Cases of pancreatitis were seen in clinical development (though not at high frequency). The class precaution is to discontinue if pancreatitis is suspected. Allergic reactions – Lixisenatide is a peptide that in trials showed a slightly elevated rate of allergic reactions. A few serious hypersensitivity reactions (like anaphylaxis or angioedema) were reported. In fact, when Adlyxin was approved, the FDA noted that hypersensitivity (e.g., urticaria and anaphylaxis) had occurred, so it’s contraindicated in patients with a prior serious allergic reaction to it. Kidney effects – As with exenatide, there were some instances of acute kidney injury or worsening renal function temporally associated with GI side effects (dehydration). Caution was advised in renally impaired patients. Immunogenicity – Being similar to exenatide (it’s another exendin-4 analog), lixisenatide can also lead to anti-drug antibodies, which might attenuate its effect over time in some patients.
- Risk profile notes: Lixisenatide is shorter acting than liraglutide or dulaglutide, thus it has a pronounced effect on postprandial glucose and relatively less effect on fasting glucose. It tended to cause a high rate of nausea initially (like other short-acting GLP-1s), but interestingly, some studies found slightly fewer serious adverse events overall, potentially because it’s a gentler agent in terms of glucose lowering. It also had a smaller impact on weight loss compared to others (a few pounds on average). Because it lacked the thyroid tumor warning, some clinicians considered it for patients where that warning was a concern – though in practice, Victoza and others were more effective, so Adlyxin never gained much market share. In head-to-head comparisons, lixisenatide was somewhat less potent than exenatide or liraglutide for HbA1c reduction, but it was generally well-tolerated aside from the GI complaints.
Lawsuits and Settlements
Adlyxin did not generate notable U.S. lawsuits during its time on the market. Its uptake was limited, and no major safety scandal emerged. No significant product liability lawsuits in the last two years (or before) have involved lixisenatide. The issues that did arise (like occasional hypersensitivity cases) were too infrequent to spur litigation. Additionally, by the time Adlyxin was available, the pancreatic cancer litigation was already underway focused on earlier incretin drugs – lixisenatide was not widely included in those cases, and indeed most plaintiffs had exposure to Byetta/Victoza/Januvia rather than the newer Adlyxin.
In the current wave of GLP-1 lawsuits (gastroparesis-related), Adlyxin is rarely, if ever, mentioned. The MDL primarily targets Ozempic, Wegovy, and Mounjaro, and now Saxenda; lixisenatide’s manufacturer Sanofi has not been named in the high-profile suits, likely because Adlyxin’s user base was small and it was pulled from the market in early 2023. If any former Adlyxin user experienced similar issues, they could theoretically bring a case, but none has surfaced publicly.
When Adlyxin was discontinued on Jan 1, 2023, Sanofi cited a strategic business decision
. There were no recalls or safety withdrawals. No settlements or government fines involved Adlyxin. In summary, Adlyxin has a clean legal record – no active or past lawsuits of note in the past two years tied to this drug, and no settlement payouts. Sanofi’s major diabetes legal battles in recent years have been more about insulin pricing (unrelated to Adlyxin) than about this GLP-1 agonist.
Tanzeum® (albiglutide) – GlaxoSmithKline (Discontinued)
Overview: Tanzeum (albiglutide) was a once-weekly GLP-1 agonist developed by GSK, approved in 2014 for type 2 diabetes. It is a unique molecule: a GLP-1 peptide dimer fused to human albumin. Tanzeum required reconstitution from a powder and was less potent in lowering blood sugar than other GLP-1 RAs. In 2017, GSK announced the discontinuation of Tanzeum globally due to low usage (a commercial decision)
. By 2018, it was phased out of the market.
Side Effects and FDA Warnings
- Common side effects: Albiglutide’s side effect profile was similar to others but with a few nuances. Nausea, diarrhea, and injection site reactions were the most common adverse events in trials
. Interestingly, albiglutide seemed to cause slightly less nausea than other GLP-1 agonists
. Many patients still experienced GI issues, but head-to-head data suggested albiglutide was better tolerated in terms of nausea/vomiting frequency (possibly due to its large size and slower tissue uptake). Injection site reactions were more frequent with albiglutide than with, say, liraglutide
. These reactions could include redness, itching, or small nodules. Some patients got injection site pain or bruising. Albiglutide also had a risk of upper respiratory tract infections noted in trials (though at similar rates to placebo)
.
- Serious risks: Thyroid C-cell tumors – Albiglutide’s ability to stimulate rodent C-cells couldn’t be fully assessed because the drug induced antibodies in rodents, interfering with the studies
. Nonetheless, the FDA included the class warning advising against use in patients with a history of medullary thyroid carcinoma or MEN-2
. Pancreatitis – Cases of pancreatitis were observed (around 0.3% of patients in trials)
, so the standard warning applies: discontinue if pancreatitis is suspected. Hypersensitivity – Albiglutide could rarely cause serious allergic reactions; a very small number of patients ( <0.1%) had significant hypersensitivity issues
. Immunogenicity – As a protein therapeutic, it had a high rate of anti-drug antibody formation, but most antibodies were low titer and didn’t neutralize the drug’s effect. There wasn’t evidence that these antibodies caused immune complex diseases or anything, but in some patients with high titers, albiglutide’s glucose-lowering effect was reduced. Cardiovascular: Albiglutide ended up showing a cardiovascular benefit in a post-hoc outcomes trial (the HARMONY trial) despite its withdrawal
, but that was too late to change its fate.
- Risk profile notes: Albiglutide was generally considered to have a milder side-effect profile at the expense of slightly less efficacy
. GSK’s own analysis noted it was less potent for A1c reduction and weight loss than competitors
. On the positive side, patients on albiglutide had a relatively low incidence of the severe nausea/vomiting that sometimes plagued other GLP-1 drugs. This could make it a gentler option for frailer patients – however, by the time it was in use, many physicians already had comfort with Victoza or were awaiting newer options. Tanzeum still had to contend with the class warnings (thyroid tumors, pancreatitis), and it required mixing before injection, which was less convenient. The injection site issues, while not dangerous, were an annoyance that other pen-based solutions minimized. Overall, Tanzeum was viewed as a somewhat underperforming GLP-1 RA, which led to its market withdrawal in the face of strong competitors.
Tanzeum Lawsuits and Settlements
Tanzeum did not see any notable lawsuits or legal actions before or after its discontinuation. Its time on the market was brief and relatively uneventful in terms of safety scandals. No major patient lawsuits are recorded against GSK for albiglutide. It wasn’t on the market long enough to accumulate a large user base that might generate postmarketing legal issues. Tanzeum’s withdrawal was attributed purely to sales performance, and GSK did not face litigation over that decision (no patients sued claiming the withdrawal harmed them, since alternative treatments were available).
During the period Tanzeum was available (2014–2018), it could have been named in the incretin-pancreatic cancer litigation, but it barely was. The bulk of those lawsuits were filed before or around 2013, and albiglutide only got approved in 2014. If any patient took Tanzeum and later was part of the MDL, it would be a very small subset. There’s no indication in the MDL records of a focus on albiglutide. Moreover, by the time cases went to trial, Tanzeum was off the table (and the MDL was ultimately resolved in favor of the companies by dismissal).
In the last two years, Tanzeum has been off the U.S. market, and no new lawsuits have involved it. GSK has not paid any settlements related to Tanzeum. Unlike Novo Nordisk and Lilly, which are battling current GLP-1 lawsuits, GSK is not part of that fray (since it no longer markets a GLP-1 RA and wasn’t implicated in the gastroparesis cases).
To conclude, Tanzeum’s legal footprint is essentially clean: no known lawsuits or settlements concerning albiglutide’s side effects or marketing. GSK quietly exited the GLP-1 arena with Tanzeum’s discontinuation, and the company’s name does not appear in the ongoing legal battles that its rivals face over this class of drugs.