HomeIngredientsSemaglutide

Active ingredient

Semaglutide

Semaglutide produces ~15% mean weight loss at 68 weeks (STEP-1) — the 2nd-most-effective GLP-1 agent in 2026, behind tirzepatide (~22%) and ahead of liraglutide (~8%).

Brand names + indications

Semaglutide is sold under 3 brand names, each with its own indication + maximum dose.

BrandIndicationMax doseFDA approved
OzempicType 2 diabetes2.0 mg/week SC2017
WegovyChronic weight management2.4 mg/week SC2021
RybelsusType 2 diabetes (oral)14 mg/day PO2019

How it works

Semaglutide is a long-acting GLP-1 receptor agonist that mimics the gut hormone GLP-1 at supra-physiologic levels. It slows gastric emptying, increases insulin secretion, decreases glucagon, and signals satiety to the brain via hypothalamic GLP-1 receptors.

Pivotal trial efficacy

−14.9%

Mean weight loss

The pivotal phase-3 trial for Semaglutide is STEP-1, which showed mean body-weight reduction at the maintenance dose.

Read the STEP-1 paper

More on Semaglutide

People also ask

Common questions readers ask

Does Ozempic cause hair loss?
Not directly. Hair shedding (telogen effluvium) is reported by some patients ~3 months into rapid weight loss — typical of any rapid-weight-loss state, not unique to GLP-1.
Full evidence-graded answer
Can you drink alcohol on Wegovy?
No hard contraindication, but alcohol tolerance often drops sharply on GLP-1. Many patients also report reduced desire for alcohol — likely a secondary effect of GLP-1 on the brain reward system.
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Can I take GLP-1 while pregnant?
No. All FDA-approved GLP-1s carry a pregnancy contraindication. Stop GLP-1 at least 2 months before planned conception due to its long half-life.
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Is it safe to take GLP-1 long-term?
Liraglutide has 15+ years of post-marketing data (Victoza approved 2010). Semaglutide has 8+ years (Ozempic approved 2017). No new class-wide safety signals have emerged in extended follow-up. Chronic use is the FDA-approved indication for both T2D and obesity.
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Do I need to exercise on Wegovy?
Yes — resistance training specifically. Without it, 25-40% of weight lost on GLP-1 comes from lean muscle. Cardio is a bonus; resistance is the non-negotiable.
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