Retatrutide (5 mg Vial) Dosage Protocol
Reconstitution and weekly-titration guide for the 5 mg Retatrutide starter vial — the GLP-1 / GIP / glucagon triple agonist researched for weight management and metabolic health.
Quickstart Highlights
Retatrutide is a triple-receptor agonist that activates the GLP-1, GIP, and glucagon receptors together — a combination studied for appetite regulation, insulin response, and energy expenditure. Its roughly six-day half-life supports once-weekly dosing. The 5 mg vial is a starter size, well suited to the low end of a titration before stepping up to a larger vial.
- Composition: 5 mg Retatrutide per vial
- Reconstitute: Add 1.0 mL bacteriostatic water → 5 mg/mL concentration
- Easy measuring: At 5 mg/mL, 1 unit (0.01 mL) on a U-100 syringe = 50 mcg (so 2 mg = 40 units)
- Storage: Lyophilized: −20 °C (−4 °F); reconstituted: 2–8 °C (35.6–46.4 °F), protected from light, use within 2–4 weeks
Dosing & Reconstitution Guide
Once-weekly subcutaneous titration; the 5 mg vial covers the initial low-dose phase
Weekly Subcutaneous Protocol (5 mg vial, 1 mL = 5 mg/mL)
| Weeks | Weekly Dose | Syringe Volume (U-100) | mL Equivalent |
|---|---|---|---|
| 1–2 | 2,000 mcg (2 mg) | 40 units | 0.40 mL |
| 3–4 | 4,000 mcg (4 mg) | 80 units | 0.80 mL |
Administration: Once weekly via subcutaneous injection. A 5 mg vial provides roughly 2–3 starter doses; advance to a 10–20 mg vial once weekly doses reach 8–12 mg. Titrate slowly to limit gastrointestinal effects.
Reconstitution Steps
- Allow the vial to reach room temperature (15–20 minutes out of cold storage).
- Draw 1.0 mL bacteriostatic water with a sterile syringe.
- Inject slowly down the vial wall to avoid foaming.
- Gently swirl or roll until fully dissolved (do not shake).
- Label with date and concentration; refrigerate at 2–8 °C, protected from light.
Result: 5 mg/mL concentration
How This Works
Retatrutide simultaneously engages three metabolic hormone receptors. GLP-1 and GIP activity influence insulin secretion and appetite, while glucagon-receptor activity is associated with increased energy expenditure and hepatic fat handling — a profile researched for greater weight reduction than single- or dual-agonist compounds.
Its long half-life of roughly six days allows steady once-weekly exposure. Gradual dose escalation is used to improve gastrointestinal tolerability as the body adapts.
Key Administration Notes
- Rotate injection sites to prevent lipohypertrophy.
- Titrate gradually; gastrointestinal effects are most common early and ease with slow escalation.
- Use new sterile insulin syringes each time; dispose in a sharps container.
- Document weekly dose, date, and site for consistency.
References
Jastreboff AM, et al. Triple-hormone-receptor agonist retatrutide for obesity — a phase 2 trial. View Source
Rosenstock J, et al. Retatrutide, a GIP/GLP-1/glucagon receptor agonist, in type 2 diabetes — a phase 2 trial. View Source
⚠️ Research & Educational Purposes Only
This information is provided for research and educational purposes only. The compounds discussed are intended for laboratory research use only and are not approved for human consumption. Always consult qualified healthcare professionals for medical advice. Individual results may vary. This is not medical advice.