GLP-1 weight management
Retatrutide
retatrutide
Investigational triple agonist (GLP-1 / GIP / glucagon). Phase 3 weight loss approached ~24%, the highest yet. Not FDA-approved; expected 2027.
- Manufacturer
- Eli Lilly
- Pivotal efficacy
- ~24% mean body-weight reduction at 48 weeks (highest dose, Phase 2) · Phase 2 (NCT04881760) / TRIUMPH Phase 3 ongoing
FDA Boxed Warning
Investigational drug. Retatrutide is not FDA-approved and is available only through clinical trials. As a GLP-1-class agent it is expected to carry the class thyroid C-cell tumor warning. Do not purchase 'retatrutide' from any online seller, no legal commercial or compounded supply exists.
Why is Retatrutide prescribed?
Retatrutide is Eli Lilly's investigational triple hormone-receptor agonist, hitting GLP-1, GIP, and glucagon receptors. It is NOT FDA-approved and not yet for sale. Phase 2 and ongoing Phase 3 (TRIUMPH program) data have shown mean weight loss approaching 24% at the highest dose, the largest of any GLP-1-class agent reported to date. Industry expectation is an FDA decision around 2027. There are no legitimate compounded or telehealth retatrutide products; any seller offering it now is operating outside the law.
How does Retatrutide work?
Where semaglutide hits one receptor and tirzepatide two, retatrutide adds a third: the glucagon receptor. Glucagon-receptor activation increases energy expenditure on top of the appetite-suppression and glycemic effects of GLP-1/GIP, which is the leading hypothesis for its larger weight-loss signal. The trade-off under study is tolerability and heart-rate effects at the highest doses.
Who qualifies for Retatrutide?
Not applicable yet, retatrutide is investigational and available only through clinical trials. When approved, expect obesity and type 2 diabetes indications mirroring the rest of the class, with the same thyroid C-cell contraindication.
How should Retatrutide be used?
Investigational. Trial dosing is once-weekly subcutaneous injection with gradual titration; final approved doses are not set.
What should I do if I forget a dose?
Not applicable, retatrutide is not commercially dosed. Trial participants follow study protocols.
How effective is Retatrutide?
~24% mean body-weight reduction at 48 weeks (highest dose, Phase 2)
- Trial:
- Phase 2 (NCT04881760) / TRIUMPH Phase 3 ongoing
- Comparator:
- vs placebo; largest GLP-1-class weight-loss signal reported to date
- Participants:
- n = 338
What side effects can Retatrutide cause?
Trial adverse events mirror the GLP-1 class (nausea, vomiting, diarrhea, dose-dependent), with attention in studies to heart-rate increase and tolerability at the top dose. Full safety profile pending Phase 3 completion.
What interactions should clinicians watch for?
As an incretin agonist it is expected to slow gastric emptying and carry the same oral-absorption and hypoglycemia-with-insulin considerations as the rest of the class. Definitive interaction data await approval.
What special precautions should I follow?
Pregnancy & lactation
Investigational; not used outside trials, which exclude pregnancy. The GLP-1-class recommendation to discontinue before conception is expected to apply.
Alcohol
No clinical guidance yet. Class-level expectation: alcohol amplifies GI side effects and the slowed-gastric-emptying interaction.
What does Retatrutide cost?
No commercial price exists. Available only via clinical-trial enrollment. Beware any website selling 'retatrutide' today, it is not a legal product.