Ozempic For Weight Loss: What Are The Dangers

  • Chimdi Okoye Bachelor of Science - BS, Pharmaceutical Science with Regulatory Affairs, Kingston University
  • Zayan Siddiqui BSc in Chemistry with Biomedicine, KCL, MSc in Drug Discovery and Pharma Management, UCL


The soaring popularity of Ozempic as a mode of weight loss has raised questions regarding its utility and potential risks. Ozempic is the brand name for an injectable medication used to control blood sugar in individuals with type 2 diabetes (T2D).1 The European Medicines Agency (EMA) authorised Ozempic in 2018, recommending its application in individuals with inadequately controlled T2D in combination with diet and exercise, either as an alternative to metformin when contraindicated or as an adjuvant therapy with other antidiabetic agents.2

Moreover, clinical data reveals Ozempic’s effective capacity to minimise the risk of cardiovascular events, such as heart attack, stroke, and mortality in diabetic patients, along with a notable reduction in body weight.3 These promising results have led healthcare professionals to currently prescribe Ozempic for weight loss.4 The drug’s efficacy and safety have been studied for specific populations, including overweight and obese individuals,5 thus this ‘off-label’ use of Ozempic is not officially approved. Nevertheless, healthcare providers assess each case individually, determining the best option by analysing the risk-benefit ratio for patients.4 Additionally, Ozempic is essentially the same medication, containing a lower dose of liraglutide, as another anti-obesity drug named Wegovy, authorised by the EMA in 2022.6

The ongoing trend of Ozempic on social media, coupled with the potential easy access to medication with or without prescription, has resulted in a shortage of Ozempic.1 The problematic aspect of this scenario lies in the potential misuse of the drug by individuals without consulting a medical professional and without entirely understanding the potential side effects.

Mechanism of action

Ozempic belongs to a class of drugs named glucagon-like peptide 1 (GLP-1) agonists. Its active component, semaglutide, acts by mimicking the GLP-1 hormone, normally present in the gut, which plays a key role in glycaemic control. Specifically, Ozempic:4,7

  1. Stimulates insulin secretion from the pancreas in response to elevated glucose levels, subsequently reducing blood sugar.
  2. Limits the release of glucagon, another hormone responsible for augmenting blood sugar.
  3. Has been associated with prolonged feelings of fullness, as it delays gastric emptying, which is the amount of time it takes for ingested food to move from the stomach into the intestines

Ultimately, semaglutide’s influence on the brain via complex gut-brain signalling pathways and neurohormonal factors may elucidate the drug’s correlation to appetite suppression and reduced food intake. Notably, some of the most prevalent adverse effects of Ozempic, such as nausea and vomiting, can also contribute to a loss of appetite.8

Common side-effects

Ozempic’s auspicious results on T2D patients are evident; however, no medication comes without adverse effects. The most frequently reported undesirable effects of Ozempic, whether selected for weight loss or T2D, include:2

While the above gastrointestinal side effects are typically dose-dependent and do not usually necessitate medical attention, they should be reported if they persist or become bothersome. Most of these events are considered moderately severe and transient, albeit, in certain instances, they have resulted in the discontinuation of treatment. It is imperative to adhere to your doctor’s guidance while using this medication, as adjustments in dosage and control tests may be necessary.2

Risks and complications

The safety profile of Ozempic, particularly regarding long-term use, remains incompletely understood as ongoing post-marketing surveillance continues reporting new information. Certain infrequent yet severe complications of Ozempic have been reported both during the drug’s clinical trials and from the general public, including:

An eye disease prevalent in patients with T2D. In a clinical study, 3% of Ozempic-treated patients developed diabetic retinopathy compared to 1.8% in the placebo group.9 The sudden and rapid glucose level decrease with semaglutide seems to be associated with an initial mitigation of a pre-existing diabetic retinopathy. The long-term effects of Ozempic in patients with a history of diabetic retinopathy are currently being studied.9

Gallstones (cholelithiasis) have been reported in patients using various GLP-1 agonists, including semaglutide. The mechanisms of these events are multifactorial and still not clearly stated.9

  • Gastrointestinal adverse effects:

Ozempic and similar medications may increase the risk of gastroparesis, a condition where there is a delay in stomach emptying without mechanical indications. Furthermore, bowel obstruction (intestinal blockage) has been reported when using Ozempic,10 with the U.S. Food and Drug Administration (FDA) also stating a potential link with ileus.11

Animal studies on Ozempic have revealed an incremental risk of developing thyroid tumours and cancer. A labelled warning has been stated by the FDA, mentioning to avoid Ozempic if there is a history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2. However, the evidence of such speculation is limited and continuous vigilance on the matter is crucial for establishing a definitive connection.12

  • Pancreatic complications:

Acute pancreatitis and pancreatic cancer have been suggested as potential secondary complications of Ozempic, although current data remains insufficient to confirm this supposition. A dose-dependent correlation between semaglutide and a rise in pancreatic enzymes lipase and amylase levels has been noted and is currently under further investigation.9

Renal function alterations have been reported in specific cases when using Ozempic and similar products. Nausea, vomiting, and diarrhoea, the most common side effects, may cause dehydration and induce acute kidney injury and other renal problems. The long-term effects of the drug in patients with chronic kidney disease are under scrutiny.9

  • Cardiovascular complications:

GLP-1 medications, including Ozempic, may increase heart rate, which, however, is not linked to severe cardiac events.9

  • Injection-site and allergic reactions:

Mild reactions at the site of the injection, such as rash, bruising, redness, and pain, have been reported by certain patients when using Ozempic. More severe hypersensitivity reactions, including anaphylactic shock and angioedema, are rare but might also occur.2

  • Drug interactions:

Ozempic may interact with numerous medications, delaying their absorption due to the gastric emptying delay it induces.2

The list of potential complications with Ozempic has not yet been concluded, as more information has come to light regarding post-market surveillance programs. Additional reported side effects of Ozempic include alterations in the taste of food or drinks2, as well as the emergence of the characteristic ‘Ozempic face’, where rapid weight loss causes facial volume depletion, sagging skin, and wrinkles.13 Conclusively, some troublesome reports of suicidal thoughts and self-harm have prompted data review for investigating associated risks.14

Who should avoid ozempic?

Ozempic may require specific attention in certain populations, such as those with impaired kidney or liver functions. It is contraindicated in those with known hypersensitivity to semaglutide and in patients with type 1 diabetes or those who developed diabetic ketoacidosis since this drug is not an insulin substitute. Paediatric and elderly populations have limited to no safety and efficacy data available. Finally, Ozempic is contraindicated and must be discontinued during pregnancy and lactation.2

Ozempic and other GLP-1 agonists vary in dosages and active ingredients, resulting in unique therapeutic profiles. Each medication is tailored to specific cases, and healthcare providers are responsible for analysing your personal, medical and drug histories to determine the most appropriate treatment. 

While Ozempic is approved for patients with T2D, an observed ‘off-label’ use for weight loss has emerged in certain populations. The immense online popularity of the drug, influenced by celebrities, along with the availability of online subscriptions through telehealth services, even at lower prices, has led to a shortage in the market. This scarcity has limited the drug’s accessibility to those really in need and has given rise to black market packages containing falsified drugs.1,15

Clinical trials for Ozempic and similar drugs primarily included specific populations, like patients with T2D and overweight (BMI above 30) or obese patients (BMI of 27 with another health-undermining weight-related condition). Therefore, the exact effects on short-term weight management in individuals outside of these categories remain unknown and may pose certain risks. The long-term side effects of the drug are still being documented, and the aforementioned risks emphasise the need for careful consideration before using this medication. Additionally, medical supervision and lifestyle modifications are pivotal when using Ozempic as discontinuation of the drug could potentially lead to weight increase.4


In summary, Ozempic’s active ingredient, semaglutide, a GLP-1 agonist, has exhibited remarkable efficacy in managing blood glucose levels in patients with T2D. Its impact on the brain and its ability to delay gastric emptying correlate with feelings of fullness and reduced appetite, marking Ozempic as a potentially powerful tool for long-term weight management. While the most common side effects include gastrointestinal issues and hypoglycaemia, its long-term undesired events are still under investigation, revealing potential risks such as diabetic retinopathy, gallstones, pancreatic complications, and an elevated risk of thyroid cancer.

Although Ozempic is officially approved for T2D, the surge in popularity and celebrity influence have led to an ‘off-label’ use for weight management, extending to populations not targeted for testing the drug. This trend has caused a shortage of Ozempic, impacting those genuinely in need and fostering illicit black market trade and falsifications. The accessibility of the drug through online prescriptions, without adequate lifestyle modifications and medical supervision, poses unknown but potentially severe consequences for populations.


  1. Basch CH, Narayanan S, Tang H, Fera J, Basch CE. Descriptive analysis of TikTok videos posted under the hashtag #Ozempic. Journal of Medicine, Surgery, and Public Health [Internet]. 2023 [cited 2024 Feb 14]; 1:100013. Available from: https://www.sciencedirect.com/science/article/pii/S2949916X23000130
  2. Ozempic | European Medicines Agency [Internet]. [cited 2024 Feb 14]. Available from: https://www.ema.europa.eu/en/medicines/human/EPAR/ozempic
  3. Husain M, Bain SC, Holst AG, Mark T, Rasmussen S, Lingvay I. Effects of semaglutide on risk of cardiovascular events across a continuum of cardiovascular risk: combined post hoc analysis of the SUSTAIN and PIONEER trials. Cardiovasc Diabetol [Internet]. 2020 [cited 2024 Feb 14]; 19:156. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7526237/
  4. Wojtara M, Mazumder A, Syeda Y, Mozgała N. Glucagon-Like Peptide-1 Receptor Agonists for Chronic Weight Management. Adv Med [Internet]. 2023 [cited 2024 Feb 14]; 2023:9946924. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10533252/
  5. Garvey WT, Batterham RL, Bhatta M, Buscemi S, Christensen LN, Frias JP, et al. Two-year effects of semaglutide in adults with overweight or obesity: the STEP 5 trial. Nat Med [Internet]. 2022 [cited 2024 Feb 14]; 28(10):2083–91. Available from: https://www.nature.com/articles/s41591-022-02026-4
  6. Wegovy | European Medicines Agency [Internet]. [cited 2024 Feb 14]. Available from: https://www.ema.europa.eu/en/medicines/human/EPAR/wegovy
  7. GLP-1 RA Mechanism of Action | Ozempic® (semaglutide) injection 0.5 mg, 1 mg, or 2 mg. novoMEDLINK [Internet]. [cited 2024 Feb 14]. Available from: https://www.novomedlink.com/diabetes/products/treatments/ozempic/about/mechanism-of-action.html
  8. Roh E, Choi KM. Hormonal Gut–Brain Signaling for the Treatment of Obesity. International Journal of Molecular Sciences [Internet]. 2023 [cited 2024 Feb 14]; 24(4):3384. Available from: https://www.mdpi.com/1422-0067/24/4/3384
  9. Smits MM, Van Raalte DH. Safety of Semaglutide. Frontiers in Endocrinology [Internet]. 2021 [cited 2024 Feb 15]; 12. Available from: https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2021.645563
  10. Sodhi M, Rezaeianzadeh R, Kezouh A, Etminan M. Risk of Gastrointestinal Adverse Events Associated With Glucagon-Like Peptide-1 Receptor Agonists for Weight Loss. JAMA [Internet]. 2023 [cited 2024 Feb 15]; 330(18):1795–7. Available from: https://doi.org/10.1001/jama.2023.19574
  11. Drug Safety-related Labeling Changes (SrLC) [Internet]. [cited 2024 Feb 15]. Available from: https://www.accessdata.fda.gov/scripts/cder/safetylabelingchanges/index.cfm?event=searchdetail.page&DrugNameID=2183
  12. Important Safety Information | Ozempic® (semaglutide) injection 0.5 mg or 1 mg [Internet]. [cited 2024 Feb 15]. Available from: https://www.ozempic.com/important-safety-information.html
  13. Humphrey CD, Lawrence AC. Implications of Ozempic and Other Semaglutide Medications for Facial Plastic Surgeons. Facial Plast Surg [Internet]. 2023 [cited 2024 Feb 15]; 39(6):719–21. Available from: http://www.thieme-connect.de/DOI/DOI?10.1055/a-2148-6321
  14. Meeting highlights from the Pharmacovigilance Risk Assessment Committee (PRAC) 27-30 November 2023 | European Medicines Agency [Internet]. [cited 2024 Feb 15]. Available from: https://www.ema.europa.eu/en/news/meeting-highlights-pharmacovigilance-risk-assessment-committee-prac-27-30-november-2023
  15. EMA alerts EU patients and healthcare professionals to reports of falsified Ozempic pens | European Medicines Agency [Internet]. [cited 2024 Feb 16]. Available from: https://www.ema.europa.eu/en/news/ema-alerts-eu-patients-healthcare-professionals-reports-falsified-ozempic-pens
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Maria Raza Tokatli

Master's degree, Pharmacy, University of Rome Tor Vergata

Master's degree holder in pharmacy and licensed pharmacist in Italy with a diverse background in medical writing, research, and entrepreneurship. Advocating for personalised approaches in medicine, and an AI enthusiast committed to enhancing health awareness and accessibility. Intrigued by the pursuit of expanding knowledge, actively staying updated on new insights in the pharmaceutical and technological fields.

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