Semaglutide dosage and protocol
Last reviewed Oct 7, 2026. Editorial policy
US regulatory status: FDA-approved drug
Semaglutide is a GLP-1 receptor agonist that mimics the incretin hormone GLP-1, reducing appetite, improving glycemic control, and promoting significant weight loss. Marketed as Ozempic (diabetes) and Wegovy (obesity), it has shown up to 15% body weight reduction in clinical trials. One of the most powerful fat loss peptides currently studied.
- Vial size: 5 mg
- Reconstitution: 2 mL bacteriostatic water
- Concentration: 2.5 mg/mL
- Administration: subcutaneous
Research areas
- Fat Loss
- Weight Management
- Glucose Regulation
- Appetite Suppression
- Metabolic Health
Quick start
- Reconstitute: Add 2.0mL bacteriostatic water → ~2.5mg/mL concentration
- Weekly dose range: 250–2400mcg (0.25–2.4mg) once weekly (gradual escalation)
- Easy measuring: At 2.5mg/mL, 1 unit = 0.01mL ≈ 25mcg on a U-100 syringe
- Storage: Lyophilized at −20°C; after reconstitution, refrigerate at 2–8°C and use within 28 days
Dosing protocol
| Phase | Dose | Frequency | Volume |
|---|---|---|---|
| Weeks 1–4 | 250 mcg (0.25 mg) | Once weekly (SC) | 0.10 mL (10 units) |
| Weeks 5–8 | 500 mcg (0.5 mg) | Once weekly (SC) | 0.20 mL (20 units) |
| Weeks 9–12 | 1000 mcg (1.0 mg) | Once weekly (SC) | 0.40 mL (40 units) |
| Weeks 13–16 | 1700 mcg (1.7 mg) | Once weekly (SC) | 0.68 mL (68 units) |
| Weeks 17+ (Maintenance) | 2400 mcg (2.4 mg) | Once weekly (SC) | 0.96 mL (96 units) |
How it works
Semaglutide is a GLP-1 receptor agonist modified with a fatty-acid side chain that binds albumin, giving a half-life of about a week. Activating GLP-1 receptors on pancreatic beta cells increases glucose-dependent insulin secretion and lowers glucagon, while receptors in the brainstem and hypothalamus reduce appetite and food reward. It also slows gastric emptying, especially early in treatment. It is FDA-approved as Ozempic (weekly injection for type 2 diabetes, including cardiovascular risk reduction and, more recently, kidney outcome indications), Rybelsus (an oral tablet for type 2 diabetes) and Wegovy (weekly 2.4 mg injection for chronic weight management, also approved to reduce cardiovascular events in adults with established cardiovascular disease and overweight or obesity). In the STEP phase 3 trials, 2.4 mg weekly produced mean weight loss of roughly 15 percent over 68 weeks in adults without diabetes, and the SELECT trial showed about a 20 percent reduction in major cardiovascular events. Weight tends to return after stopping in trial follow-up. Most side effects are gastrointestinal and dose-related, which is why labelled dosing escalates gradually over about 16 weeks.
Units chart for a 5 mg vial
| Water added | Strength | 1 unit = | 250 mcg | 500 mcg | 1 mg | 1.7 mg |
|---|---|---|---|---|---|---|
| 1 mL | 5 mg/mL | 50 mcg | 5 units | 10 units | 20 units | 34 units |
| 2 mL | 2.5 mg/mL | 25 mcg | 10 units | 20 units | 40 units | 68 units |
| 3 mL | 1.67 mg/mL | 16.7 mcg | 15 units | 30 units | 60 units | over 1 mL |
Units on a U-100 insulin syringe (100 units = 1 mL).
Pages for each vial size and water volume
Reconstitution steps
- Draw 2.0mL bacteriostatic water with a sterile syringe
- Inject slowly down the vial wall to minimize foaming; avoid shaking
- Gently swirl or roll the vial until fully dissolved
- Label with reconstitution date and refrigerate at 2–8°C (35.6–46.4°F), protected from light; use within 28 days
Storage
Evidence: FDA label. From the US prescribing information of the approved product. It applies to that product only.
Applies to: Ozempic pens (label). Wegovy single-dose pens: refrigerate; before the cap is removed they may be kept at 8–30 °C for up to 28 days.
- Powder or unopened: Not a powder: ready-made pens. Before first use: refrigerator, 2–8 °C (36–46 °F). Do not freeze.
- Mixed or in use: After first use, an Ozempic pen may be kept at 15–30 °C (59–86 °F) or in the refrigerator.
- Use within: 56 days after mixing or first use
- Light: Keep the pen cap on (Ozempic) or the pen in its carton (Wegovy) to protect it from light.
Compounded or "research" semaglutide vials are not covered by the label. Ask the pharmacy for its beyond-use date.
Sources: Ozempic prescribing information and Instructions for Use (DailyMed); Wegovy prescribing information (DailyMed)
Store lyophilized at -20°C. After reconstitution, refrigerate at 2-8°C and use within 28 days.
Important notes
- Research use only
- Dose escalation is critical to minimize GI side effects (nausea, vomiting)
- May cause muscle loss — combine with resistance training
- Ozempic/Wegovy pharmaceutical equivalent
- Monitor for rare pancreatitis risk
Supplies
- Bacteriostatic water
- Insulin syringes (U-100)
- Alcohol swabs