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MetabolicIn StockSubQ injection

Retatrutide

Acylated peptide · GIP/GLP-1/glucagon triple agonist · Synthetic

Half-life

~6d

After administration

Delivery Method

SubQ injection

Route of administration

Storage (Lyophilised)

12-24 months

2–8°C

Storage (Reconstituted)

4–6 weeks

Refrigerate at 2-8C

Known For

Triple agonist (GLP-1/GIP/Glucagon). Most potent weight loss peptide currently available. Phase 3 trials showed average 28.7% body weight loss. Also being studied for NASH/fatty liver disease and sleep apnea.

Mechanism of Action

Triple agonist — GIP + GLP-1 + glucagon receptors. Most potent weight loss peptide in trials. Glucagon component adds thermogenesis.

Body vs. External Supply

🔴 Exogenous (replaces natural)

Brand / Trade Names

No brand name yet (Investigational — Eli Lilly) Expected approval: ~2027

Typical Research Dosage

Titrate: 0.5mg → 1mg → 1.5mg → 2mg → 3mg → 4mg → 6mg weekly. Increase weekly or hold if sides are bad. Max ~8-12mg. SubQ once weekly.

Vial Duration Guide

10mg vial: ~5-6 weeks with standard titration (first vial). At 6mg/wk maintenance = ~1.7 weeks per vial.

Recommended Vial Size

★ 10mg vials Standard titration (0.5→6mg) uses ~10mg over first 5-6 weeks ✓. Fits neatly within shelf life. At 6mg/wk maintenance, order more frequently.

Time to Effects

EARLY: 1-2 weeks FULL: 12-24 weeks Week 1-2: Appetite suppression kicks in quickly. GI side effects (nausea, diarrhoea) are common early — this is the glucagon receptor activity. Week 2-4: Measurable weight loss. Energy changes from glucagon receptor activation. Week 4-8: Significant fat loss visible. Titration still progressing toward maintenance. Week 12-24: Full effect at maintenance dose. Phase 3 trials showed ~28.7% body weight loss at 48 weeks. Liver fat reduction measurable by 24 weeks. Minimum commitment: 12 weeks. Optimal: 24-48 weeks.

Contraindications & Do Not Combine

• Do NOT combine with Tirzepatide, Semaglutide, or Survodutide (never stack GLP-1 agonists) • Do NOT combine with CagriSema (GLP-1 overlap) • Caution with insulin or sulfonylureas (hypoglycaemia risk)

Common Side Effects

Nausea (23%), diarrhoea (22%), vomiting (11%), constipation (10%), ⚠️ dysesthesia/paraesthesia (20.9% at 12mg — NEW safety signal from TRIUMPH-4)

Drug Interactions

Expected similar to tirzepatide: insulin, sulfonylureas, oral contraceptives. Glucagon component may affect hepatic drug metabolism.

Reversibility

Expected weight regain similar to other GLP-1 agonists. Limited long-term data — still in Phase 3.

Key Peer-Reviewed References

All studies are published in indexed journals unless otherwise noted.

• Jastreboff et al. (2023) Phase 2 Trial. NEJM 389(6):514-526. DOI: 10.1056/NEJMoa2301972 • Lilly TRIUMPH-4 Phase 3 (2025): 28.7% weight loss at 68wk, NCT05931367 • Meta-analysis: PMC12026077 (2025) — 3 RCTs, 878 patients • NOT YET FDA APPROVED — Phase 3 program ongoing (7 trials, results expected 2026)

Research Disclaimer

Almost all data is preclinical (animal or in-vitro). No large-scale randomised controlled human trials are available for most compounds on this catalogue. This information is provided for research reference only.

Storage Requirements

Clinical trial supply only — standard peptide cold chain 2-8°C

State	Condition	Duration
Lyophilised (sealed)	2–8°C	12-24 months
Reconstituted	2-8C	4–6 weeks

Reconstitution Note

Reconstitute with bacteriostatic water (BAC water). Do not shake vigorously -- swirl gently to dissolve. Inject BAC water slowly down the side of the vial to avoid denaturing the peptide.

Video Resources

Retatrutide discussed by researchers & practitioners

Independent educational content from researchers, clinicians, and science communicators. Not affiliated with Pepnerd — provided as supplementary reading.

Educational resources only. The videos above are independent third-party content from researchers, clinicians, and science communicators. Pepnerd is not affiliated with any of these creators and does not endorse or make any claims based on their content. All products are sold strictly for in-vitro scientific research.

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Quick Reference

Half-life	~6 days (t½ ~136hrs)
Delivery	SubQ injection
Typical dose	0.5mg
Storage (lyoph.)	2–8°C
Storage (recon.)	4–6 weeks
Endogenous?	Exogenous (replaces natural)
Suppression	None known
WADA	Not listed — investigational
FDA status	Phase 3 trials