Semaglutide

Semaglutide is FDA-approved for three indications: type 2 diabetes mellitus (as Ozempic, subcutaneous, or Rybelsus, oral), chronic weight management in adults and adolescents aged 12+ (as Wegovy, subcutaneous), and reduction of major adverse cardiovascular events in adults with overweight or obesity plus established cardiovascular disease (as Wegovy). It is not approved for cosmetic or non-medical weight loss.

In the STEP 1 trial, adults without diabetes on Wegovy 2.4 mg weekly lost an average of 14.9% of body weight at 68 weeks, compared with 2.4% on placebo. About one-third of participants lost ≥20%. Weight loss plateaus around 65–70 weeks and is maintained with continued treatment; discontinuation typically leads to substantial regain.

Same active molecule (semaglutide), different branding, dosing, and FDA indications. Ozempic is approved for type 2 diabetes at doses of 0.25–2.0 mg weekly. Wegovy is approved for chronic weight management at doses of 0.25–2.4 mg weekly. Rybelsus is the oral tablet form (3–14 mg daily) for type 2 diabetes only. Insurance coverage differs substantially across the three.

Tirzepatide (Mounjaro/Zepbound) is a dual GLP-1/GIP agonist and has produced higher weight loss in head-to-head comparison. In SURMOUNT-5 (NEJM 2025), tirzepatide produced 20.2% weight loss vs 13.7% for semaglutide at 72 weeks — a 47% greater relative reduction. Tirzepatide is generally considered more potent for weight loss; semaglutide has the larger cardiovascular outcomes dataset (SELECT trial). See our dedicated comparison article for a detailed breakdown.

The most common side effects are gastrointestinal: nausea (up to 44% during titration), diarrhea or constipation, vomiting, and abdominal discomfort. These are largely dose-dependent and improve with slower titration. Rare but serious risks include pancreatitis, gallbladder disease, worsening of diabetic retinopathy with rapid glycemic improvement, and a boxed warning for medullary thyroid carcinoma based on rodent data.

Indefinitely, if the indication persists. Semaglutide is a chronic therapy for chronic conditions — both diabetes and obesity are relapsing-remitting. Discontinuation studies consistently show that the majority of lost weight returns within a year. The STEP 4 trial demonstrated that stopping semaglutide at week 20 led to regaining about two-thirds of lost weight by week 68.

As of April 2026, large-scale compounding of semaglutide is not FDA-permitted. The FDA removed both Ozempic and Wegovy from the drug shortage list in early 2025, which ended the regulatory pathway that had allowed compounded versions during the 2022–2024 supply crisis. 503A patient-specific compounding remains possible under narrow circumstances, but mass-produced 'semaglutide from a compounder' is no longer lawful.

All weight loss — pharmacologic or behavioral — includes some lean-mass component. Analyses of STEP trial body composition data suggest approximately 25–40% of total weight loss on semaglutide is lean mass, similar to the proportion seen in dietary weight loss. Resistance training and adequate protein intake (≥1.2 g/kg/day) substantially mitigate this effect.

No absolute contraindication, but two cautions apply. First, semaglutide slows gastric emptying, which can prolong and intensify alcohol's effects. Second, emerging observational data suggest GLP-1 agonists reduce craving for alcohol — some patients report spontaneously reducing intake. Heavy drinking also increases pancreatitis risk, which is already a concern with GLP-1 therapy.

No withdrawal syndrome or acute dangers from stopping semaglutide. However, the therapeutic effects end when the drug clears — which takes approximately 5 weeks at full elimination due to the 7-day half-life. Appetite returns, and weight regain typically begins within weeks. For type 2 diabetes, glucose control deteriorates back toward pre-treatment baseline. Sudden discontinuation is not medically dangerous but rarely clinically advised.