What it is
Semaglutide is a GLP-1 (glucagon-like peptide-1) receptor agonist first approved in 2017 for type 2 diabetes (Ozempic) and later for chronic weight management (Wegovy) in 2021. It mimics the incretin hormone GLP-1, improving glycemic control and reducing appetite.
Mechanism of action
Semaglutide binds GLP-1 receptors, enhancing glucose-dependent insulin secretion, suppressing glucagon, slowing gastric emptying, and acting centrally on hypothalamic appetite centers to reduce caloric intake.
Half-life: ~7 days β supports once-weekly dosing.
Evidence summary
The STEP trial program (1β8) demonstrated average body-weight reductions of 12β15% at 68 weeks versus placebo. SUSTAIN trials showed strong HbA1c and cardiovascular risk reductions in type 2 diabetes.
Typical dosing protocols
- Week 1β4: 0.25 mg subcutaneous once weekly (initiation)
- Week 5β8: 0.5 mg once weekly
- Week 9β12: 1.0 mg once weekly
- Maintenance: titrate up to 1.7β2.4 mg weekly based on response and tolerance
Side effects & safety
- GI: nausea, vomiting, diarrhea, constipation (typically peak during titration)
- Hypoglycemia risk when combined with insulin or sulfonylureas
- Rare: pancreatitis, gallbladder issues, injection-site reactions
- β’ Personal/family history of medullary thyroid carcinoma or MEN2
- β’ Severe GI disease, active pancreatitis
- β’ Pregnancy
Cited studies
- Wilding JPH, Batterham RL, Calanna S, et al. (2021). Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). New England Journal of Medicine.PMID 33567185DOI 10.1056/NEJMoa2032183Read source β
- Davies M, FΓ¦rch L, Jeppesen OK, et al. (2021). Semaglutide 2.4 mg once a week in adults with overweight or obesity, and type 2 diabetes (STEP 2). The Lancet.PMID 33667417DOI 10.1016/S0140-6736(21)00213-0Read source β
- Marso SP, Bain SC, Consoli A, et al. (2016). Semaglutide and Cardiovascular Outcomes in Patients with Type 2 Diabetes (SUSTAIN-6). New England Journal of Medicine.PMID 27633186Read source β
All content is for research and educational purposes. Peptides described are sold for laboratory research use only and are not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional before beginning any protocol.