Semaglutide
aka Ozempic · Wegovy · Rybelsus
A long-acting GLP-1 receptor agonist and the most rigorously studied weight-management peptide in modern medicine, with cardiovascular outcome data from tens of thousands of patients.
Mechanism of action
Binds the glucagon-like peptide-1 receptor, amplifying glucose-dependent insulin secretion, suppressing glucagon, slowing gastric emptying, and acting on hypothalamic arcuate nucleus circuits that regulate satiety.
Doses used in published studies
Trials titrated from 0.25 mg weekly to 2.4 mg weekly over 16–20 weeks (STEP program). Oral formulations studied at 3–50 mg daily.
These figures describe what researchers administered under supervision. They are reported for accuracy and are not a protocol, recommendation, or substitute for clinical guidance.
Reported benefits
- 14.9% mean body-weight reduction at 68 weeks (STEP 1)
- 20% reduction in major adverse cardiovascular events (SELECT)
- Substantial HbA1c reduction in type 2 diabetes
- Improvements in knee osteoarthritis pain and sleep apnea severity in later trials
Risks & unknowns
- Nausea, vomiting, constipation in up to 44% of participants
- Rare pancreatitis and gallbladder events
- Lean-mass loss without resistance training and adequate protein
- Thyroid C-cell tumors observed in rodents (boxed warning)
Legal & regulatory status
Approved by the FDA for type 2 diabetes (2017) and chronic weight management (2021). Legal by prescription in the US, EU, UK, Canada, and Australia. Compounded and 'research-only' semaglutide sold outside pharmacy channels is not FDA-approved.
Check status in your state or country →Key studies
- Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1)
New England Journal of Medicine · 2021
- Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (SELECT)
New England Journal of Medicine · 2023