Educational content only — this is not medical advice. Nothing here is a recommendation to buy, obtain, or use Semaglutide. Talk to a licensed clinician before making health decisions.
What it is
Semaglutide is a long-acting glucagon-like peptide-1 (GLP-1) receptor agonist, a modified peptide with a fatty-acid side chain that slows absorption and promotes albumin binding, giving it a half-life of about one week. It is administered as a once-weekly subcutaneous injection (Ozempic, Wegovy) or as a daily oral tablet (Rybelsus). It mimics endogenous GLP-1, amplifying glucose-dependent insulin secretion, suppressing glucagon, slowing gastric emptying, and reducing appetite through central pathways.
What the evidence shows
The STEP 1 trial (NEJM 2021; 1,961 adults with overweight/obesity, 68 weeks) reported mean weight loss of 14.9% with semaglutide 2.4 mg versus 2.4% with placebo. STEP 3, 4, and 5 trials confirmed durable weight loss and cardiometabolic improvements in varied populations. The SUSTAIN programme established HbA1c reductions of approximately 1.5–1.8 percentage points in type 2 diabetes. The SELECT cardiovascular outcomes trial (NEJM 2023; 17,604 participants) showed a 20% relative risk reduction in major adverse cardiovascular events in adults with obesity and established cardiovascular disease.
Risks & unknowns
Common adverse events are gastrointestinal — nausea, vomiting, diarrhea, constipation — and are usually dose-dependent and transient. Gallbladder disease, pancreatitis, hypoglycemia (especially with insulin or sulfonylureas), and injection-site reactions have been reported. The STEP trials had low discontinuation rates overall, but nausea and vomiting were the leading reasons for stopping treatment. Medullary thyroid carcinoma and multiple endocrine neoplasia type 2 are contraindications based on rodent data. Long-term real-world safety databases continue to accumulate.
Legal / regulatory status
Semaglutide is FDA-approved for type 2 diabetes (Ozempic), chronic weight management (Wegovy), and cardiovascular risk reduction in adults with obesity/CVD (Wegovy). It is a prescription medication. Compounded or unregulated "research" versions are not authorized and carry quality risks.