Retatrutide
An investigational triple agonist drawing weight-loss interest.
The short version
- Why people discuss it
- Studied for obesity, type 2 diabetes and related conditions. Lilly reports Phase 3 results, but retatrutide remains investigational and has no approved public-use regimen.
- What it is
- One molecule acting at GIP, GLP-1 and glucagon receptors. “GLP-3” is an informal nickname, not a receptor or formal drug class.
- Biggest caution
- Products sold outside the trial supply may have unknown ingredients, contamination or incorrect amounts. Trial results do not verify the identity or safety of a seller’s vial.
- Stack context
- A triple agonist is not a three-drug stack. No add-on stack is established by the source reviewed here.
Dose and frequency reference
Reference only — not a recommendation. Amounts describe source-specific community examples, selected study regimens or the named product label. They do not establish safety, effectiveness, product identity, or a suitable dose for any person. Never convert mg, mcg, or IU into syringe “units” without the exact product concentration.
Source agreement describes reported practice, not clinical validation.
Subcutaneous injection in trials and community discussion
Study reference · Population-specific- Amount
- 2 mg initiation
- Frequency
- Once weekly
- Duration / phase
- First 4 weeks before trial-style escalation
Investigational trial initiation, not approved dosing. Sponsor Phase 3 targets use four-week steps through 2, 4, 6, 9 and 12 mg as assigned; Peptidepedia’s 8/10 mg Phase 3 ladder is incorrect. Study observation periods do not establish a repeatable community cycle. Reference only; this does not establish safety, effectiveness or individual suitability.
Reference source · reviewed 2026-09-27Compare reported schedules
Saved source material reviewed 2026-09-27. Multiple pages from one publisher count as one source family; agreement does not establish what most people use. SC means subcutaneous; IM intramuscular; IP intraperitoneal.
- PeptideDosages — saved source reviewed September 27, 2026
2 mg weekly initiation; Phase 2 and Phase 3 schedules separated; Phase 3 2→4→6→9→12 mg at 4-week steps.
- Peptidepedia — saved source reviewed September 27, 2026
0.5 mg start and claimed Phase 3 2→4→6→8→10→12 mg; internally mixes different study contexts.
Evidence & sources · Investigational human trials
Community references document claims and reported practices. They are not clinical evidence. Some references contain supplier promotions or market treatment; their commercial context is identified in the source label.
- Lilly: What to know about retatrutide — July 2026 updateManufacturer update · Checked 2026-09-12
- PeptideDosages — saved source reviewed September 27, 2026Community reference · Checked 2026-09-27
- Peptidepedia — saved source reviewed September 27, 2026Community reference · Checked 2026-09-27
- Lilly: TRIUMPH-4 study design and escalationManufacturer update · Checked 2026-09-27