GLP-1 receptor agonist
FDA-approved weekly injectable / daily oral for diabetes and weight management (Novo Nordisk).
| Class / type | GLP-1 receptor agonist |
|---|---|
| Category | Metabolic & Weight |
| Status (Jul 2026) | FDA-approved |
Semaglutide is one of the most studied and widely prescribed metabolic drugs in the world. It is a GLP-1 receptor agonist made by Novo Nordisk and sold under three brand names: Ozempic (weekly injection for type 2 diabetes), Wegovy (weekly injection for weight management), and Rybelsus (a daily oral tablet for diabetes).
Unlike most compounds profiled on this site, semaglutide is a fully approved prescription medicine with large, high-quality human trials behind it. Note that 'research grade' semaglutide sold in vials online is not the approved product and has not been through the same quality controls.
Semaglutide mimics GLP-1, a natural incretin hormone released from the gut after eating. It enhances glucose-dependent insulin secretion, suppresses glucagon, and slows how quickly the stomach empties. It also acts on appetite centers in the brain, which is why users describe reduced hunger and quieter 'food noise'.
Because insulin release is glucose-dependent, the risk of low blood sugar from semaglutide alone is low; hypoglycemia becomes a concern mainly when it is combined with insulin or sulfonylureas.
In the STEP program (obesity), adults on 2.4 mg weekly lost roughly 15% of body weight over 68 weeks, versus about 2-3% on placebo. In the SUSTAIN diabetes trials, it lowered A1c by around 1.5-1.8%.
The SELECT trial was a landmark: in people with established cardiovascular disease and obesity but not diabetes, semaglutide reduced major cardiovascular events (heart attack, stroke, cardiovascular death) by about 20%. It has also shown benefit in a non-cirrhotic MASH (fatty liver) trial.
Substantial, reliable weight loss and strong A1c control, backed by large randomized trials rather than anecdote.
Proven cardiovascular risk reduction in a high-risk group, plus an oral option (Rybelsus) for people who prefer not to inject. Many users find it more tolerable than tirzepatide.
The most common side effects are gastrointestinal: nausea, vomiting, diarrhea and constipation, usually worst during dose escalation and often easing over time.
Rare but serious risks include pancreatitis, gallbladder disease, and gastroparesis (delayed stomach emptying). There is a boxed warning for thyroid C-cell tumors based on rodent studies, and it is contraindicated in people with a personal or family history of medullary thyroid carcinoma or MEN2. Weight tends to return after stopping unless habits are maintained.
Semaglutide is a prescription medicine that should be used under medical supervision, with the dose titrated up slowly to limit nausea. Because effects reverse on discontinuation, clinicians generally frame it as a long-term therapy paired with diet and activity rather than a short course.
Reliable appetite / 'food noise' reduction; gentler tolerability than tirzepatide for many.
FDA-approved prescription drug (Ozempic, Rybelsus, Wegovy). Gray-market 'research' vials are NOT the approved product.