Retatrutide
Retatrutide is an investigational injectable peptide designed to activate the GLP-1, GIP and glucagon receptors at once, currently in phase 3 trials for obesity and type 2 diabetes.
Regulatory status: Investigational. Published phase 2 data exist and phase 3 trials are under way, but retatrutide has no FDA or other regulatory approval and no approved label.
Default vial
10 mg
Default mix
2 mL
Reported range
1–4 mg
Draw (U-100)
20 u
Investigational triple agonist; dose ranges are the least standardized on this list.
What it is
- A triple hormone receptor agonist targeting GLP-1, GIP and glucagon receptors.
- An engineered single peptide, structurally related to the GIP/GLP-1 peptide scaffolds.
- Given once weekly by subcutaneous injection, titrated up to 12 mg over 48 weeks in the phase 2 trial.
- Subcutaneous, investigational use only.
How it is described to act
- 1
Administered subcutaneously in trial settings, on a weekly schedule like related incretin peptides.
- 2
Reported to reach tissues bearing GLP-1, GIP and glucagon receptors, including liver, adipose tissue, pancreas and central feeding centres.
- 3
Proposed to act across three receptor systems at once, with the glucagon component hypothesised to add an energy-expenditure effect beyond appetite suppression.
- 4
In the phase 2 cohort this was associated with substantial weight reduction; longer-term and comparative outcomes are still being studied.
What the research has looked at
Phase 2 obesity trial
- In a phase 2 trial (NEJM, 2023), Jastreboff et al. reported substantial mean weight reduction at the 12 mg dose over 48 weeks compared with placebo.
- The authors noted weight loss had not plateaued by week 48 in the higher-dose groups, so the 48-week figure may understate the eventual effect.
Phase 3 programme
- Phase 3 trials in obesity and related metabolic conditions are registered and ongoing; results had not been published at the time this profile was written.
Strength of evidence: Limited human evidence
Peer-reviewed phase 2 randomised data exist, but phase 3 efficacy and safety results and regulatory review are not complete.
Some human data exist, but they are small, short, or not designed to answer the questions people ask online.
Reported cautions and unknowns
- Nausea, diarrhoea, vomiting and constipation were the most common adverse events in the phase 2 trial, mostly during dose escalation.
- Investigators observed heart-rate increases, which the authors attributed to the glucagon-receptor component.
- Long-term pancreatitis, gallbladder, thyroid and pregnancy safety data are not established because the trial programme is incomplete.
References
Handling this vial
- Lyophilized vials are generally stored at 2–8 °C and kept out of light; once reconstituted with bacteriostatic water they are refrigerated and commonly discarded after 28 days.
- Mix by aiming water down the vial wall and rolling gently — do not shake — and never re-freeze a reconstituted vial.
- Pep-Tidy cannot verify what is in your vial. Ask your supplier for a current Certificate of Analysis (HPLC/MS).
Retatrutide questions people ask
How do you reconstitute Retatrutide?
A common starting point for a 10 mg vial of Retatrutide is 2 mL of bacteriostatic water, which gives 5 mg per mL. Aim the water down the inside wall of the vial, let it dissolve on its own, and roll gently instead of shaking. Pep-Tidy's reconstitution calculator will recalculate the numbers for any other vial size or water volume you use.
How many units of Retatrutide is one dose?
At 5 mg per mL, that works out to about 20 units on a U-100 insulin syringe for a 1000 mcg dose. Change the vial size, water volume, or target dose in the calculator and the syringe reading updates with it. This is arithmetic, not a dosing recommendation.
What dosing schedule is reported for Retatrutide?
Published and community sources describe 1–4 mg, subcutaneous, once weekly, typically run 12 weeks on. These figures describe what has been reported, not what anyone should take — talk to a licensed clinician first.
How should Retatrutide be stored?
Lyophilized Retatrutide vials are generally kept at 2–8 °C and out of light. Once reconstituted with bacteriostatic water they are refrigerated and commonly discarded after about 28 days. Never re-freeze a reconstituted vial and never shake it.
Read this before you act on anything above
Everything on this page is a summary of what other people have published — it is not medical advice, not a recommendation, and not a dosing instruction. Reported dose ranges describe what appears in the literature or in community protocols, not what anyone should take. Talk to a licensed clinician before using any peptide.