Semaglutide (20mg)
Semaglutide is a GLP-1 agonist with a ~7-day half-life. The 20 mg vial is the most cost-effective option for long-term maintenance. Administered subcutaneously once weekly.
Reviewed by the AllPeptides.eu Editorial Team·Last reviewed: 2026-06-16
Educational information. Not medical advice, and no efficacy claim is implied. Regulatory approval is not a use recommendation by AllPeptides.eu.
⚠️ For informational/educational purposes only. Not medical advice. We do not sell any products. Self-treatment carries serious risks — consult a healthcare professional. Disclaimer
Research monograph
See the full Semaglutide encyclopedia page with mechanism, evidence tier, related variants and research context.
How It Works
A GLP-1 agonist with 94% homology. It reduces appetite, slows gastric emptying, and improves glycemic control. Half-life of ~7 days.
Quick Start
- Reconstitution: Add 2.0 mL bacteriostatic water → 10.0 mg/mL.
- Weekly Range: 0.25–2.4 mg once weekly.
- Easy Dosing: At 10 mg/mL, 1 unit = 0.01 mL = 100 mcg.
- Storage: Lyophilized: −20 °C; reconstituted: 2–8 °C, use within 28 days.
Titration Schedule (2 mL = 10.0 mg/mL)
Route: Subcutaneous | Frequency: Once weekly
| Week | Dose | Units (per injection) |
|---|---|---|
| Weeks 1–4 | 0.25 mg | 2.5 Units (0.03 mL) |
| Weeks 5–8 | 0.5 mg | 5 Units (0.05 mL) |
| Weeks 9–12 | 1.0 mg | 10 Units (0.10 mL) |
| Weeks 13–16 | 1.7 mg | 17 Units (0.17 mL) |
| Weeks 17+ | 2.4 mg | 24 Units (0.24 mL) |
Studies report administration once weekly. The high concentration (10 mg/mL) results in very small injection volumes. One 20 mg vial is sufficient for ~8 weeks of maintenance at 2.4 mg/week.
Related compounds
Reconstitution Steps
- Draw 2.0 mL of bacteriostatic water.
- Inject slowly down the side of the vial.
- Swirl gently until dissolved.
- Date the vial; refrigerate at 2–8 °C.
Protocol Overview
- Goal: Chronic weight management via GLP-1.
- Schedule: Weekly injections for 16+ weeks.
- Advantage: Fewer vials, small volumes.
Dosing Protocol
- Wks 1–4: 0.25 mg/wk.
- Wks 5–8: 0.5 mg/wk.
- Wks 9–12: 1.0 mg/wk.
- Wks 13–16: 1.7 mg/wk.
- Wks 17+: 2.4 mg/wk.
- Break between cycles: After completing a cycle, a 4–8 week washout period is recommended before repeating. Semaglutide has a long half-life (~7 days)—the body needs time to fully clear the peptide.
Washout & Cycle Restart
When can I restart?
After completing a cycle, a 4–8 week washout period is recommended before repeating. Semaglutide has a long half-life (~7 days)—the body needs time to fully clear the peptide.
Minimum wait period: 4 weeks
Storage Instructions
- Lyophilized: −20 °C.
- Reconstituted: 2–8 °C; use within 28 days.
Important Notes
- Gradual titration reduces GI side effects.
Potential Benefits & Side Effects
Potential Benefits:
- 10–15% body weight loss.
- Glycemic control.
- Fewer vials needed for long-term use.
Potential Side Effects:
- GI: nausea, diarrhea—typically mild.
- Rare: pancreatitis.
⚠️ Serious Warnings & Long-Term Risks
The following warnings are based on published literature, FDA labels, and post-marketing surveillance. They do not constitute medical advice. Consult a healthcare professional.
Thyroid C-cell tumors (medullary thyroid carcinoma)
In rodents, semaglutide caused dose-dependent thyroid C-cell tumors (medullary carcinoma). Contraindicated in patients with personal/family history of MTC or MEN 2.
📄 FDA Boxed Warning — Ozempic® / Wegovy® LabelAcute pancreatitis
Reports of acute pancreatitis, including necrotizing. Discontinue if suspected. Increased risk with history of pancreatitis.
📄 FDA Label — Ozempic®Cholelithiasis & cholecystitis
Increased risk of gallstones due to rapid weight change. 1.5–3% incidence in clinical trials.
📄 STEP Trials — NEJM 2021References
- NCBI Bookshelf – StatPearls — Semaglutide Pharmacology
View Source - Mayo Clinic — Semaglutide
View Source
Recommended Supplements
Vitamin B12 (Methylcobalamin)
Vitamin D3 + K2
Omega-3 Fish Oil (EPA/DHA)
Protein / Collagen
Fiber Supplement (Psyllium)
External Sources & Regulatory Status
Regulatory Approvals
Ozempic® / Wegovy® · Type 2 diabetes / Obesity (2017)
Ozempic® / Wegovy® · Type 2 diabetes / Obesity (2018)
Ozempic® · Type 2 diabetes (2018)
Ozempic® · Type 2 diabetes (2021)
Ozempic® / Wegovy® · Type 2 diabetes / Obesity (2019)
Ozempic® / Wegovy® · Type 2 diabetes / Obesity (2018)
Ozempic® / Wegovy® · Type 2 diabetes / Obesity (2019)
Approved worldwide (7+ countries)
Educational information. Not medical advice, and no efficacy claim is implied. Regulatory approval is not a use recommendation by AllPeptides.eu.
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