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Metabolic

Retatrutide peptide reference

Triple agonist (GIP/GLP-1/glucagon) in late-stage trials. Most powerful weight-loss data to date.

Last reviewed May 6, 2026 Human data Not FDA approved
Peppi reviewing Retatrutide notes
Default dose label2 mg
Preferred routeSubQ
Frequency label1× weekly
Storage window28 days mixed

Evidence snapshot

Human data

Evidence maturityHuman data
Phase 2 (TRIUMPH-2) complete with strongest-ever weight-loss data; Phase 3 ongoing

Investigational — not approved

Route map

How records are usually labeled

1 SubQ

Rotate weekly between abdomen, thigh, and upper arm.

Vial timeline

Storage cues to log

Before mixRefrigerate 2–8 °C; do not freeze.
After mixRefrigerate 2–8 °C, use within 28 days.
Use-by cue28 days after mixing
Mixed vial window28 days
Use this as a record-keeping cue, not a replacement for product labeling.

Peppi workflow

From vial to review

Vial 10 mg vial
Dose 2 mg
Route SubQ
Review 28d storage

Peppi turns scattered dose, vial, route, storage, note, and report details into one record trail.

Educational reference only

This page helps you understand what to track for Retatrutide. It is not medical advice, a prescription, or a recommendation to use this peptide. Discuss dose, route, timing, storage, and safety with a qualified healthcare professional.

Overview

Retatrutide is a synthetic 39-amino-acid triple agonist developed by Eli Lilly that activates GIP, GLP-1, and glucagon receptors simultaneously. Phase 2 trials (TRIUMPH-2) reported up to 24% body weight reduction at 48 weeks — the most dramatic weight-loss data published for any pharmacotherapy. Phase 3 trials are ongoing; not yet FDA-approved.

Also known as: LY3437943, Triple G.

Severe obesity research (Phase 3)T2D researchFuture commercial weight-management indication (pending approval)

Mechanism and timing snapshot

Triple agonist of GIP, GLP-1, and glucagon receptors. Adds glucagon activation to the dual incretin mechanism — increases energy expenditure on top of appetite suppression and gastric slowing.

Onset labelNot listed
Catalog onset field, when available.
Half-life label144 hr
~6 days; weekly dosing
Duration label168 hr
Catalog duration field, when available.
subQ High
oral Negligible

Tracking defaults

These values come from Peppi's catalog so records can be prefilled consistently. They should be reviewed against your clinician's instructions before logging real-world use.

Catalog default dose2 mg
Catalog dose range2 mg - 12 mg
Default routeSubQ
Frequency label1× weekly
Best time labelSame day each week, any time of day.
Food noteNone for the injectable form (not yet commercially available).

Catalog protocol note

Trial protocol: 2 mg weekly × 4 weeks → escalate every 4 weeks up to 12 mg max. (Final marketed protocol pending Phase 3 results.)

Routes and site notes

Available route labelsSubQ
Preferred route labelSubQ
Common site labelsAbdomen, Thigh, Upper arm
Site rotation noteRotate weekly between abdomen, thigh, and upper arm.

Chemistry

SequenceModified GIP backbone with C20 fatty diacid; 39 amino acids
Amino acids39
Molecular formulaC221H343N51O66
Molecular weight4731.4 Da

Vial, reconstitution, and storage

Supply formLyophilized powder (compounded only — no commercial form yet)
Typical vial size10 mg
DiluentBacteriostatic water
Diluent volume2 mL
Concentration noteCompounded 10 mg in 2 mL → 0.04 mL = 2 mg starting dose.
Before reconstitutionRefrigerate 2–8 °C; do not freeze.
After reconstitutionRefrigerate 2–8 °C, use within 28 days.
Reconstituted shelf life28 days
Light sensitiveYes
Freeze/thaw warningYes

Safety notes

Common and rare side effects listed in the catalog

  • Nausea (~30–40%)
  • Diarrhea or constipation
  • Decreased appetite
  • Fatigue
  • Pancreatitis
  • Increased heart rate
  • Gallbladder issues

Contraindications and warnings

  • Personal/family history of medullary thyroid carcinoma
  • MEN 2 syndrome
  • Pregnancy
  • Pancreatitis history
  • Not yet FDA-approved.
  • Glucagon component may raise heart rate and blood glucose acutely — monitor.
  • Long-term safety data still accumulating.

Other considerations

  • Most powerful weight-loss data to date — but Phase 3 not yet complete.
  • Glucagon receptor activation is a new mechanism in this class — long-term effects less known than semaglutide/tirzepatide.
  • Available only via compounding pharmacies until FDA approval.

Evidence and regulatory context

Evidence levelPhase 2 (TRIUMPH-2) complete with strongest-ever weight-loss data; Phase 3 ongoing
FDA approvedNo
Regulatory statusInvestigational — not approved
Prescription requiredNo
Approved countriesNot listed

Stacking and cycle notes

Stacks well withNot listed
Avoid combining noteOther GLP-1, GIP or glucagon agonists
Typical cycle labelongoing
Typical break labelNot typically cycled
Cycle guidanceUsed continuously per trial protocols; cycling not established.

Tracking tips

  • Bleeding-edge — Phase 3 still running. Long-term safety unknown.
  • Compounded supply quality varies significantly — vet your source.
  • Strongest weight-loss data published, but tolerability mirrors tirzepatide GI profile.

References

Track it in Peppi

Keep Retatrutide records organized.

Use Peppi for dose logs, vial inventory, storage dates, reminders, journal notes, photos, and clinician-ready reports.

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FAQ

What should I track for Retatrutide?

Track the peptide name, dose amount and unit, route, vial label, timing, reconstitution or expiration dates, storage notes, and any symptoms or questions for clinician review.

Does Peppi tell me how to use Retatrutide?

No. Peppi organizes educational reference and your own records. Protocol decisions should come from a qualified healthcare professional.

Can I export Retatrutide records?

Peppi is designed to keep dose logs, vial inventory, journal notes, and reports easier to review and export.

Last reviewed: May 6, 2026