Weight-loss medications known as GLP-1 receptor agonists, including popular drugs such as Wegovy and Mounjaro, have seen a significant rise in use recently, accompanied by increasing reports of side effects. While some adverse reactions are well documented, others remain under investigation or anecdotal, prompting calls for further research.
Gastrointestinal symptoms are among the most commonly reported side effects. Patients frequently experience nausea, vomiting, diarrhea, and constipation. These effects are understood to result from the drugs’ mechanism, which slows gastric emptying and modifies gut-brain signaling. Clinical trials have consistently registered these issues, and they are described as very common in patient information leaflets. Most manufacturers note that such symptoms usually resolve over time.
There are concerns about eye-related conditions linked to GLP-1 use, particularly among individuals with diabetes. Research indicates an increased risk of age-related macular degeneration in this population. Additionally, non-arteritic ischemic optic neuropathy (NAION), a rare condition that can lead to sudden and permanent vision loss, has been flagged as a potential side effect. While pharmaceutical companies acknowledge this risk—mentioning it specifically for Wegovy in product literature—experts emphasize that NAION occurrences are very rare.
Reports of unexpected pregnancies among women using GLP-1 medications have raised questions about possible interactions with fertility and contraceptive effectiveness. Some experts suggest these drugs may reduce the efficacy of oral contraceptives or enhance fertility by promoting weight loss, though conclusive scientific evidence is still lacking. Male fertility effects have not been extensively studied. In light of uncertainties, health authorities such as the UK’s Medicines and Healthcare products Regulatory Agency advise against the use of GLP-1 medications during pregnancy or when planning to conceive.
Social media platforms have highlighted noticeable changes in facial appearance among some users, a phenomenon sometimes termed "Ozempic face." This includes sunken eyes, increased wrinkles, and sagging skin, which experts attribute to rapid weight loss rather than the drugs themselves. Similarly, hair thinning and hair loss have attracted attention after preliminary research suggested a possible association with GLP-1 medication use in adults with type 2 diabetes. Hair loss is listed as a potential side effect in the patient leaflets for Mounjaro and Wegovy, although researchers caution that it may be related to the metabolic and nutritional changes accompanying rapid weight loss rather than a direct drug effect.
Another emerging term is "Ozempic foot," describing a bony appearance and pain in the feet reported anecdotally by some users. This is not currently recognized in official patient information. Podiatrists note that rapid weight loss, regardless of cause, can diminish the cushioning fat in the heels and balls of the feet, potentially leading to discomfort.
As GLP-1 receptor agonists gain popularity, the medical community continues to monitor their safety profile. While some side effects are well established, others require additional study to determine causality and mechanisms. Physicians and patients are encouraged to weigh the benefits and risks, maintain open communication, and follow regulatory guidance on the use of these medications.