GLP-1 Receptor Agonist
Semaglutide
Also known as: GLP-1 SMG, Ozempic, Wegovy
An FDA-approved GLP-1 receptor agonist with one of the largest human clinical trial bases of any compound on this site. Sold by research-chemical vendors under coded names like 'GLP-1 SMG' — this profile is about the actual approved drug, semaglutide.
A note on naming
Semaglutide is sold by many research-chemical vendors under coded or abbreviated names — "GLP-1 SMG" is one example — rather than its actual name. It's worth being direct about this: semaglutide is not a novel, unstudied research peptide. It's the active ingredient in two FDA-approved prescription drugs (Ozempic, for type 2 diabetes, and Wegovy, for chronic weight management), backed by one of the largest clinical trial programs of any compound discussed on this site. "Research use only" semaglutide sold outside the pharmacy supply chain is not manufactured, tested, or regulated the same way as the approved product, even though the underlying molecule is the same.
Overview
Semaglutide is a GLP-1 (glucagon-like peptide-1) receptor agonist, a class of drugs that mimics an incretin hormone your gut releases after eating. It was first approved for type 2 diabetes (Ozempic, 2017) and later for chronic weight management (Wegovy, 2021), following trial results showing substantial, sustained weight loss.
Proposed Mechanism of Action
Semaglutide activates GLP-1 receptors, which slows gastric emptying, increases satiety signaling in the brain, and enhances glucose-dependent insulin secretion — the combined effect reduces food intake and improves glycemic control.
Research Context
The cited STEP 1 trial randomized 1,961 adults with overweight or obesity (without diabetes) to either 2.4 mg once-weekly subcutaneous semaglutide or placebo, alongside lifestyle intervention, for 68 weeks. The semaglutide group lost a mean of 14.9% of body weight versus 2.4% with placebo, and the most common adverse events were gastrointestinal (nausea, diarrhea), generally mild-to-moderate and transient. This is one of several large Phase 3 trials in the STEP program; we've cited the pivotal one here.
Regulatory Status
Semaglutide is FDA-approved under specific brand names, doses, and formulations, dispensed by prescription through licensed pharmacies. Compounded or "research use only" versions sold outside that pathway are a distinct regulatory and quality-control situation — the FDA has issued public warnings about compounded semaglutide specifically, including concerns about dosing accuracy and product purity in some tested samples.
Limitations of the Current Evidence
- The cited trial excluded people with diabetes; separate trials (the SUSTAIN program) cover semaglutide's original diabetes indication.
- Long-term data beyond the trial period (including the "STEP 1 extension" literature on weight regain after discontinuation) is worth reading before assuming results are permanent without continued treatment.
Research-Setting Dosing (as reported in literature)
| Route | Range (as reported) | Frequency | Notes |
|---|---|---|---|
| Subcutaneous injection | 2.4–2.4 mg | Once weekly (following a dose-escalation schedule) | STEP 1 trial (Wilding et al., 2021), 68 weeks. This is the FDA-approved Wegovy maintenance dose, not a starting dose — the trial used a gradual dose-escalation schedule before reaching 2.4 mg. |
Figures above are extracted directly from the cited preclinical/research literature. They describe what researchers administered to study subjects (frequently animal models) — they are not human dosing recommendations and are not medical advice.
Cited Studies
Once-Weekly Semaglutide in Adults with Overweight or Obesity
Wilding JPH, Batterham RL, Calanna S, et al. (STEP 1 Study Group) · New England Journal of Medicine · 2021
Human clinical trial (Phase 3, randomized, double-blind, placebo-controlled, 1,961 subjects)View source →
Last updated August 1, 2026