Vial sizes vary by vendor. Smaller bottles are usually 3 mL; larger bottles are often 10 mL. Match the label on the vial you actually bought, then use the calculator below if you need to adjust.
Overview
Retatrutide is a triple agonist peptide targeting GLP-1, GIP, and glucagon receptors, making it one of the most potent metabolic peptides available.
PubMed evidence
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PMID 37366315 (2023) — Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial. Human trial evidence; supports clinical context without changing the protocol.
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PMID 37385280 (2023) — Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-controlled, parallel-group, phase 2 trial conducted in the USA. Human trial evidence; supports clinical context without changing the protocol.
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PMID 40563436 (2025) — Retatrutide-A Game Changer in Obesity Pharmacotherapy. Review evidence; use as context, not primary protocol input.
Preparation
Recon: 10 mg vial + 2 mL BAC (5 mg/mL).
Protocol
| Period | Dose | Units (@ 5mg/mL) | Frequency |
|---|---|---|---|
| Weeks 1-4 | 2.5 mg | 50 u | 1x/week |
| Weeks 5-8 | 5 mg | 100 u | 1x/week |
| Weeks 9-12 | 7.5 mg | 150 u | 1x/week |
| Weeks 13-16 | 10 mg | 200 u | 1x/week |
| Weeks 17-20 | 12.5 mg | 250 u | 1x/week |
| Weeks 21-24 | 15 mg | 300 u | 1x/week |
Cycle
12 weeks on, 4 weeks off. Half-life is approximately 6 days.