Skip to content
CompoundSci
All peptides
Research vial labelled Retatrutide, a Incretin / GLP-1 class peptide studied in preclinical and clinical literature

Retatrutide

GIP / GLP-1 / glucagon triple agonist

Triple agonist across GLP-1, GIP and glucagon receptors. Phase 2 results have been published.

Still investigational. The glucagon arm raises heart rate in the trial data, which is the thing to read about first.

General profile

Class
Incretin / GLP-1 class
Evidence
Mixed or moderate evidence
Studied dose range
1 mg titrating upward in trials
Frequency in protocols
Weekly
Route
Subcutaneous
Half life
~6 days
Reconstitution
2 mL bacteriostatic water per 10 mg vial
Storage
Refrigerated, ~30 days

Timing and cycling in the literature

Usually dosed in the morning window

Once weekly, same day each week

Long acting, so timing is about consistency. The glucagon arm raises resting heart rate, which is easier to monitor on a fixed schedule.

Reported cycle: 24 weeks on, run continuously in trials

Trial design mirrors the other incretins: slow titration held over months.

Watch for: Resting heart rate. The glucagon arm raised it consistently in the trial data.

What it conflicts with

Three separate questions, kept separate. A hard stop means the mechanisms must not run together at all and timing does not fix it. A syringe rule means the same day is fine but one barrel is not. Redundancy is not dangerous, it is paying twice to hit one target.

  • Hard stopTiming

    Retatrutide + GLP-1 analogs

    Never run two incretin agonists together

    Overlapping GLP-1 signalling with an added glucagon arm. The combined gastrointestinal and heart rate effects are additive and untitratable.

  • Hard stopTiming

    Retatrutide + Tirzepatide

    Never run two incretin agonists together

    Same receptor family, same side effect profile, no additional studied benefit. Choose one and titrate it slowly.

  • Separate syringesSame day fine, same syringe not

    Retatrutide + Anything else, including another incretin

    Solo in the barrel, always

    Every incretin gets its own syringe and its own draw, including alongside another incretin. Protocol stacking is a real thing and is not a hard stop, but co-drawing is never part of it.

  • Pick oneSame day fine, same syringe not

    Retatrutide + Another incretin in a designed protocol

    Stacking is a protocol decision, not redundancy

    Multi-incretin work uses different receptor balances, so it is not the same button pressed twice. It only makes sense with the job named first, each dose lowered against solo use, titration on response, protein defence and side effect monitoring. Insulin or sulfonylureas are physician territory.

Most syringe compatibility claims here are practice and expert consensus, not peer reviewed mixing studies. A clear liquid after mixing does not prove the compounds are still active, and cloudiness, particles or gelling means discard. Active cancer, pregnancy, major cardiac care and heavy immunosuppression override every stack preference on this page.

See how Retatrutide fits your week

The injection scheduler spaces doses using the clinical timing data, flags the pairs above before you draw them, and tells you why.

Model this in the injection scheduler

The studies

Human trials: Phase 2 complete, phase 3 ongoing. Not approved.

Open questions: Resting heart rate rise of roughly 5 to 10 bpm is reported, and no long-term outcome data exists yet.

Published papers

Indexed from Europe PMC and refreshed weekly. Each link opens the paper itself.

Search the full literature