Peptide LibraryRetatrutide dosage in published studies and labels
These are the doses used for Retatrutide in FDA labelling and published clinical studies, reported as each source states them, one row per regimen. They describe what was studied or approved for a specific population. They are not a recommendation, and none of them is a dose for any individual.
Research and educational reference only. This is not medical advice, and no figure on this page is a dosing recommendation.
Last checked against primary sources:
Studied regimens and sources
Retatrutide has no FDA-approved dosage. Human dosing comes from Eli Lilly's registered trial programme, where doses of 1–12 mg subcutaneously once weekly were studied in phase 2, reached by stepwise titration inside a monitored protocol. The published phase 3 trials (TRIUMPH-1 and TRIUMPH-2, 80 weeks; TRANSCEND-T2D-1, 40 weeks) gave 4, 9 or 12 mg once weekly after escalation from 2 mg every four weeks. Lilly plans to submit retatrutide to the FDA in Q1 2027; until a label exists there is no established maintenance dose outside a trial.
| Human dosing established | Yes |
|---|---|
| Studied dose range | 1–12 mg once weekly in phase 2 and 3 trials |
| Route | Subcutaneous |
| Frequency | Once weekly |
| Duration studied | 36–48 weeks in the published phase 2 trials; 40–80 weeks in the published phase 3 trials |
| Titration | Stepwise escalation inside the trial protocol, typically starting at 2 mg and increasing every 4 weeks. The published dose range is the range studied, not a schedule for use. |
| Evidence level | Clinical Trial Evidence |
| Last reviewed | 2026-11-08 |
Research-reported dosing
Doses as studied, one row per regimen. Different trials used different regimens; they are listed separately rather than averaged.
| Study / context | Population | Dose | Route | Frequency | Duration | Outcome studied | Source |
|---|---|---|---|---|---|---|---|
| Phase 2 obesity trial (Jastreboff et al., 2023)Clinical trial · Phase 2 double-blind randomised placebo-controlled trial | Adults with obesity, or overweight with a weight-related condition (n=338) | 1 mg, 4 mg, 8 mg or 12 mg | Subcutaneous | Once weekly | 48 weeks | Percentage change in body weight | Jastreboff AM et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. N Engl J Med. 2023. |
| Phase 2 type 2 diabetes trial (Rosenstock et al., 2023)Clinical trial · Phase 2 double-blind randomised controlled trial | Adults with type 2 diabetes (n=281) | 0.5 mg, 4 mg, 8 mg or 12 mg | Subcutaneous | Once weekly | 36 weeks | Change in glycated haemoglobin | Rosenstock J et al. Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo- and active-controlled, parallel-group, phase 2 trial. Lancet. 2023. |
| Phase 2 MASLD substudy (Sanyal et al., 2024)Clinical trial · Phase 2 substudy | Adults with obesity and metabolic dysfunction-associated steatotic liver disease | 1 mg, 4 mg, 8 mg or 12 mg | Subcutaneous | Once weekly | 48 weeks | Liver fat content | Sanyal AJ et al. Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease. Nat Med. 2024. |
| Phase 3 type 2 diabetes monotherapy trial (TRANSCEND-T2D-1; NCT06354660)Clinical trial · Phase 3 double-blind randomised placebo-controlled trial | Adults with type 2 diabetes inadequately controlled by diet and exercise (n=537) | 4 mg, 9 mg or 12 mg | Subcutaneous | Once weekly | 40 weeks | Change in glycated haemoglobin; body weight a key secondary endpoint | Bajaj HS et al. Efficacy and safety of retatrutide, a GIP, GLP-1, and glucagon receptor agonist, in people with type 2 diabetes and inadequate glycaemic control with diet and exercise (TRANSCEND-T2D-1): a double-blind, randomised, phase 3 trial. Lancet. 2026. |
| TRIUMPH-1 phase 3 obesity trial (Jastreboff et al., 2026)Clinical trial · Phase 3 double-blind randomised placebo-controlled trial | Adults with obesity or overweight without type 2 diabetes (n=2339) | 4 mg, 9 mg or 12 mg | Subcutaneous | Once weekly | 80 weeks | Percentage change in body weight at week 80 | Jastreboff AM et al. Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity (TRIUMPH-1). N Engl J Med. 2026. |
| TRANSCEND-T2D-2 — phase 3 versus semaglutide; topline reported by Lilly 2026-10-28, not yet publishedClinical trial · Phase 3 open-label randomised active-controlled trial; topline only | Adults with type 2 diabetes on metformin with or without an SGLT2 inhibitor (n=1298) | 9 mg or 12 mg (comparator semaglutide 2 mg) | Subcutaneous | Once weekly | 80 weeks | Change in HbA1c versus semaglutide at week 80 | NCT06260722 — Effect of Retatrutide Compared With Semaglutide in Adult Participants With Type 2 Diabetes and Inadequate Glycemic Control With Metformin With or Without SGLT2 Inhibitor (TRANSCEND-T2D-2) |
Where sources disagree
- Retatrutide is not an FDA-approved product. Several DailyMed listings appear under its name, but they are submitted by a cross-border e-commerce labeller rather than representing an FDA-approved prescribing information document. A DailyMed listing is not evidence of approval.
- The 12 mg weekly figure is the highest dose studied in phase 2, reached by protocol-driven titration under trial monitoring. It is not a target dose, and dose-dependent gastrointestinal adverse effects were reported across the escalation range.