Semaglutide (Semaglutide (GLP-1 Receptor Agonist))
A GLP-1 receptor agonist approved for type 2 diabetes and chronic weight management. Marketed as Ozempic/Wegovy. Achieves 15-17% body weight loss in clinical trials.
How it works
Binds GLP-1 receptors in the pancreas to stimulate insulin secretion, in the brain to reduce appetite, and in the GI tract to slow gastric emptying. 94% homology to native GLP-1.
Key facts
- Molecular weight: 4,114 Da
- Half-life: 7 days (168 hours)
- Bioavailability: High (SubQ ~89%), Moderate (oral ~1% with SNAC)
- Storage: Refrigerated 2-8°C. In-use pen: room temperature up to 56 days.
Dosing overview
- Typical dose: 0.25 mg → titrate up to 2.4 mg
- Frequency: Once weekly
- Duration: Ongoing (chronic)
- Route: Subcutaneous injection
Protocol notes
- Start low at 0.25 mg once weekly for 4 weeks (this is a tolerance dose, not a therapeutic one).
- Increase roughly every 4 weeks: 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg as tolerated.
- Hold at the lowest dose that controls appetite/weight; not everyone needs the full 2.4 mg.
- Stay on the same weekday each week to keep levels steady.
Reported benefits
- Significant weight loss (15-17%)
- Improved glycemic control
- Cardiovascular risk reduction
- Reduced food cravings
- Lower HbA1c
Possible side effects
- Nausea and vomiting
- Diarrhea or constipation
- Abdominal pain
- Pancreatitis (rare)
- Gallbladder issues
- Muscle mass loss
Research
- STEP 1 Trial: Semaglutide 2.4mg for weight management (2021): Participants lost mean 14.9% body weight vs 2.4% with placebo over 68 weeks with once-weekly injection.
- SELECT cardiovascular outcomes trial with semaglutide (2023): Semaglutide reduced major adverse cardiovascular events by 20% in overweight/obese adults without diabetes.
Compare Semaglutide
Research and educational reference only. Not medical advice.