Retatrutide — All Topics
Index of every retatrutide topic we cover — mechanism, trials, dosing, safety, access.
Retatrutide is Eli Lilly's investigational triple-agonist for obesity and type 2 diabetes — the first drug to activate GLP-1, GIP, and glucagon receptors in one molecule. It is not yet FDA-approved. This is the index of every topic we cover.
Related topic hubs
- Compare — See how retatrutide stacks up against Mounjaro, Wegovy, and Zepbound
- Safety — Full safety signal review
- Trials & FDA — TRIUMPH program + FDA timeline
Retatrutide at a glance
| Attribute | Value |
|---|---|
| Development code | LY3437943 |
| Sponsor | Eli Lilly |
| Mechanism | Triple agonist — GLP-1 + GIP + glucagon receptors |
| Administration | Once-weekly subcutaneous injection |
| Current phase | Phase 3 (TRIUMPH program) |
| Phase 2 peak weight loss | -24.2% at 48 weeks (12 mg dose, NEJM 2023) |
| Phase 3 peak weight loss | -28.7% at 68 weeks (TRIUMPH-4, knee osteoarthritis cohort) |
| Indications studied | Obesity, type 2 diabetes, MASH, sleep apnea, knee OA, cardiovascular outcomes |
| Brand name | Not yet announced |
| Expected FDA filing | Likely 2026–2027 (after TRIUMPH-1 primary readout) |
Where to start
Depending on what brought you here:
- New to retatrutide? What Is Retatrutide? and How it works.
- Comparing drugs? Retatrutide vs Tirzepatide is the head-to-head most people search for.
- Worried about side effects? Side effects & safety and the full safety topic hub.
- Trying to get access? Cost & how to get it and clinical trial sign-up.
- Tracking approval? FDA approval timeline and the clinical trials tracker.
What's next in 2026
TRIUMPH-4 (knee osteoarthritis, 68 weeks) read out in December 2025 with a headline 28.7% weight loss. The next major readouts expected in 2026:
- TRIUMPH-1 — obesity, the pivotal registration trial. This is the readout that triggers FDA filing.
- TRIUMPH-2 — obesity in type 2 diabetes.
- TRIUMPH-3 — obesity in cardiovascular disease.
- TRIUMPH-5 — head-to-head vs tirzepatide in obesity (body-weight primary; NCT06662383).
- TRIUMPH-Outcomes — cardiovascular and kidney outcomes (CV composite includes HF events; multi-year; NCT06383390; not recruiting).
Bookmark the trials tracker — we update it as each readout is published.
All retatrutide articles
18 articles
Can You Build Muscle on Retatrutide?
Retatrutide is not anabolic. How testosterone and GH peptides — not retatrutide — build the physiques in viral transformation posts.
Updated June 2026
How Does Retatrutide Work? Mechanism of Action Explained
The world's first triple agonist explained — how GLP-1, GIP, and glucagon receptors work together to reduce appetite and increase energy expenditure.
Updated June 2026
Microdosing Retatrutide & GLP-1 Drugs: What the Research Shows
Current evidence on sub-therapeutic dosing and dose-splitting of GLP-1 receptor agonists.
Updated July 2026
Retatrutide and Alcohol: What We Know
No direct studies exist on retatrutide and alcohol, but GLP-1 receptor agonist research points to reduced intake and liver effects.
Updated February 2026
Retatrutide and Pregnancy: What Triple Agonism Means for Fertility and Safety
Three receptors, three pregnancy concerns. What GLP-1, GIP, and glucagon receptor research means for retatrutide and reproductive safety.
Updated March 2026
Retatrutide Brand Name: What Will It Be Called?
Eli Lilly hasn't announced a brand name for retatrutide yet. Expect it close to FDA approval in 2027.
Updated February 2026
Retatrutide Half-Life and Pharmacokinetics
Retatrutide has a ~6-day half-life achieved through fatty acid albumin binding — comparable to semaglutide (~7 days) and tirzepatide (~5 days).
Updated February 2026
Retatrutide Pill vs Injection: Is There an Oral Formulation?
Retatrutide is injection-only. Here's why there's no pill, how the injection works, and how oral GLP-1 alternatives compare.
Updated February 2026
Retatrutide Statistics & Trial Data
The citable data hub — retatrutide weight-loss and safety figures by dose, with a primary source on every number.
Updated July 2026
Retatrutide vs CagriSema (Cagrilintide + Semaglutide): Triple Agonist vs Amylin + GLP-1 Combo
Cagrilintide vs retatrutide: triple agonist vs amylin + GLP-1 combo — 28.7% vs 22.7% weight loss, different receptors, and stacking considerations.
Updated February 2026
Retatrutide vs Mazdutide: Triple vs Dual Agonist Compared
How the triple agonist retatrutide compares to the dual agonist mazdutide on weight loss, diabetes, and liver fat data.
Updated June 2026
Retatrutide vs Mounjaro vs Ozempic
How the three generations of weight loss drugs compare — single, dual, and triple agonists.
Updated February 2026
Retatrutide vs Orforglipron: Injectable Triple Agonist vs Oral GLP-1
Retatrutide produces 28.7% weight loss via injection. Orforglipron offers 12.4% weight loss as a daily pill. Both are from Eli Lilly.
Updated February 2026
Retatrutide vs Survodutide
Two next-generation obesity drugs that both include glucagon agonism — how the triple and dual agonist approaches compare.
Updated February 2026
Retatrutide vs Tirzepatide (Zepbound): Triple Agonist vs Dual Agonist
Retatrutide produces 28.7% weight loss (triple agonist) vs tirzepatide's 22.5% (dual agonist). A head-to-head trial is underway.
Updated February 2026
Retatrutide vs Wegovy: Triple Agonist vs GLP-1
Retatrutide produces nearly double the weight loss of Wegovy, but Wegovy is available now with proven cardiovascular protection.
Updated February 2026
Retatrutide vs Zepbound: What's the Difference?
Same manufacturer, different drugs. Retatrutide adds glucagon agonism for 28.7% vs Zepbound's 22.5% weight loss.
Updated February 2026
What Is Retatrutide (GLP-3)?
The world's first triple agonist weight loss drug — how it works, what the trials show, and why people call it GLP-3.
Updated June 2026