Semaglutide
Weight Management
In plain English
Semaglutide is a medicine that mimics GLP-1, a natural gut hormone your body releases after eating. It slows how fast the stomach empties and reduces appetite, so most people feel full sooner and eat less. It is usually given as a once-weekly injection under the skin (compounded troche and other forms also exist). It is used to help with blood sugar control and weight management, typically alongside diet and activity changes. Nausea and other stomach symptoms are the most common side effects, especially when the dose is being increased.
The science
Semaglutide is a long-acting glucagon-like peptide-1 (GLP-1) receptor agonist. Activating the GLP-1 receptor increases glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and acts on hypothalamic appetite centers to reduce energy intake. The branded product has robust randomized human evidence: in the 68-week STEP 1 trial (n=1,961 adults with overweight/obesity, no diabetes), once-weekly 2.4 mg semaglutide plus lifestyle produced a mean 14.9% weight loss versus 2.4% for placebo. A trial extension showed participants regained roughly two-thirds of the lost weight within a year of stopping, underscoring that obesity is chronic and benefit depends on continued treatment. The most common adverse effects are gastrointestinal (nausea, vomiting, diarrhea, constipation), usually mild-to-moderate and worse during dose escalation; pancreatitis and gallbladder events are recognized rarer risks. Important context: compounded semaglutide is not an FDA-approved product, and the efficacy/safety data above come from the manufacturer's branded formulation, not compounded versions.
References
- Wilding JPH et al., N Engl J Med 2021 (STEP 1)
- Wilding JPH et al., Diabetes Obes Metab 2022 (STEP 1 withdrawal extension)