Semaglutide (5 mg Vial) Dosage Protocol
Semaglutide is a GLP-1 receptor agonist with ~94% sequence homology to endogenous human GLP-1. With a half-life of approximately 7 days, it enables once-weekly subcutaneous dosing. It is the active compound in FDA-approved Ozempic (T2D) and Wegovy (chronic weight management).
⚡ Quickstart Highlights
Dosing & Reconstitution Guide
Route: Subcutaneous | Frequency: Once weekly (same day each week)
| Week | Weekly Dose | U-100 Units | Volume (mL) | Notes |
|---|---|---|---|---|
| Weeks 1–4 | 0.25 mg (250 mcg) | 10 units | 0.10 mL | Starting dose |
| Weeks 5–8 | 0.5 mg (500 mcg) | 20 units | 0.20 mL | |
| Weeks 9–12 | 1.0 mg (1,000 mcg) | 40 units | 0.40 mL | |
| Weeks 13–16 | 1.7 mg (1,700 mcg) | 68 units | 0.68 mL | |
| Weeks 17+ | 2.4 mg (2,400 mcg) | 96 units | 0.96 mL | Weight management ceiling |
Reconstitution Steps
- Draw 2.0 mL bacteriostatic water.
- Inject slowly down the inside glass wall; avoid foaming.
- Gently swirl until dissolved. Do not shake.
- Label with reconstitution date. Refrigerate at 2–8°C, use within 28 days.
Supplies Planning
| Item | 8 Weeks | 16 Weeks | 28 Weeks |
|---|---|---|---|
| Semaglutide vials (5 mg each) | 2 vials | 4 vials | 7 vials |
| Insulin syringes (U-100) | 8 | 16 | 28 |
| Bacteriostatic water (10 mL) | 1 × 10 mL | 1–2 × 10 mL | 2–3 × 10 mL |
| Alcohol swabs | 1 × 100-pack | 1 × 100-pack | 1 × 100-pack |
Mechanism of Action
Semaglutide is a synthetic analog of human GLP-1 (glucagon-like peptide-1) with two key structural modifications: (1) an amino acid substitution at position 8 conferring resistance to DPP-4 enzymatic degradation, and (2) a C18 fatty diacid chain attached at position 26 via a linker, enabling albumin binding that extends the half-life to approximately 7 days.
Its mechanism is multifaceted: it enhances glucose-stimulated insulin secretion, suppresses glucagon release, slows gastric emptying, and reduces appetite through central nervous system GLP-1 receptor pathways — particularly in the hypothalamus and brainstem. The combination of peripheral and central effects produces both glycemic control and significant caloric intake reduction.
Research Findings & Safety Profile
- STEP 1 trial (NEJM, 2021): mean 14.9% body weight reduction vs 2.4% placebo over 68 weeks at 2.4 mg/week.
- STEP 2 (T2D population): 9.6% weight loss; HbA1c reduction of 1.6 percentage points.
- SURMOUNT comparison: slightly less weight loss than tirzepatide at matched timepoints.
- Most common adverse effects: nausea, diarrhea, vomiting — dose-dependent and transient, worst during escalation.
- SUSTAIN-6 and SELECT trials demonstrated cardiovascular risk reduction in T2D and high-risk obesity populations.
- Rare but reported: pancreatitis, gallbladder disease, injection-site reactions.
Storage
| State | Temperature | Duration | Notes |
|---|---|---|---|
| Lyophilized | −20°C (−4°F) | Up to 24 months | Dry, dark, avoid moisture |
| Reconstituted | 2–8°C (35–46°F) | Up to 28 days | Avoid freeze-thaw; light-protected |