lookindex

Semaglutide

Also known as Wegovy, Ozempic, Rybelsus

Proven, approved weight loss for people who meet prescribing criteria. It is not a cosmetic shortcut: side effects are common and weight tends to return after stopping.

Information only. Not medical advice. Talk to a doctor before you start, stop or change anything.

What people claim

  • Melts fat quickly
  • Works for anyone who wants to lean out
  • You keep the results when you stop

What the evidence shows

  • In STEP 1, 1,961 adults lost 14.9% of body weight over 68 weeks against 2.4% on placebo.[1]
  • A year after stopping, people in the extension study had regained about two-thirds of the weight they lost.[2]
  • Trials enrolled people with obesity or overweight plus a related health problem. They do not tell you what happens if you are already a healthy weight and want to look leaner.[1]

Known risks

  • Nausea, diarrhoea, vomiting and constipation are common.[3]
  • Boxed US warning: thyroid C-cell tumours in rodents. Not for people with a personal or family history of medullary thyroid cancer or MEN 2.[3]
  • Label warnings include pancreatitis, gallbladder disease, kidney injury, low blood sugar, raised heart rate and suicidal thoughts.[3]
  • Hair loss was reported in 3% of people, against 1% on placebo.[3]
  • NAION, a sudden eye condition that can cause vision loss, is a very rare side effect affecting up to 1 in 10,000 people.[4]
  • Compounded versions: FDA had 990 adverse event reports by 31 May 2026, including hospitalisations linked to dosing errors.[5]
  • Fake pens circulate. Report any you find to your regulator.[6]

Reported side effects

Moderated user reports are not open yet, so nothing is shown here. They will be labelled as unverified personal accounts.

Legal status

A summary, not legal advice. Rules change, and sport bans are separate.

United States

Prescription

FDA approved. Compounded versions are not FDA approved and are not reviewed for safety or quality.

United Kingdom

Prescription

Licensed. MHRA warns against pens bought online.

Australia

Prescription

Approved by TGA.

European Union

Prescription

Authorised through the European Medicines Agency.

Sources

  1. 1.STEP 1 trialNew England Journal of Medicine, 2021
  2. 2.Weight regain after withdrawal of semaglutide: STEP 1 extensionDiabetes, Obesity and Metabolism, 2022
  3. 3.US prescribing information for injectable semaglutideUS FDA
  4. 4.PRAC concludes NAION is a very rare side effect of semaglutideEuropean Medicines Agency, 2025
  5. 5.FDA's concerns with unapproved GLP-1 drugs used for weight lossUS FDA
  6. 6.MHRA seizes illegal medicines worth almost £45m in 2025MHRA UK

Profile last checked 7 Nov 2026.