Weight loss
Retatrutide, simplified.
Also called "GLP-3", triple agonist
Human studiesAn experimental weight-loss drug that copies three hormones at once. It has produced the largest weight loss seen so far in trials, but it is not approved yet.
- Size
- 39 amino acids
- How it is taken
- Weekly injection (in trials)
- Status
- Investigational, not approved
- Available sizes
- Vials: 5 mg, 10 mg, 15 mg, 20 mg, 30 mg, 60 mg
What is it?
Retatrutide acts on three hormone signals: GLP-1, GIP and glucagon. The glucagon part may help the body burn more energy, on top of eating less.
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What studies show
- In peopleIn its first large Phase 3 trial, people on the top dose lost around 28 to 30% of their body weight on average.
- In peopleIt also eased knee osteoarthritis pain in people with obesity in that trial.
What we don’t know yet
- Long-term safety, since it is still in trials.
- When, or whether, the FDA will approve it.
Side effects and cautions
- Stomach side effects similar to other GLP-1 drugs.
- Products sold online as "research retatrutide" are not the tested drug and have no quality control.
Is it legal?
Not FDA-approved. Only legally available inside clinical trials.
Dosage & schedule evidence
How to read published schedules
Third-party schedules are not established clinical dosing standards. Human dose, frequency, and long-term safety may be unknown.
| Measurement | Meaning |
|---|---|
| 1 mg | 1,000 mcg (mass) |
| 100 U-100 units | 1 mL (volume, not dose) |
For source context, see third-party published protocols ↗. North Star does not validate these schedules.
Consult your doctor before considering any peptide for personal use. Educational only, not administration guidance.
Common questions
What is Retatrutide?
An experimental weight-loss drug that copies three hormones at once. It has produced the largest weight loss seen so far in trials, but it is not approved yet. Retatrutide acts on three hormone signals: GLP-1, GIP and glucagon. The glucagon part may help the body burn more energy, on top of eating less.
What does the research say about Retatrutide?
In its first large Phase 3 trial, people on the top dose lost around 28 to 30% of their body weight on average. It also eased knee osteoarthritis pain in people with obesity in that trial.
Is Retatrutide FDA approved?
Not FDA-approved. Only legally available inside clinical trials.
What are the side effects of Retatrutide?
Stomach side effects similar to other GLP-1 drugs. Products sold online as "research retatrutide" are not the tested drug and have no quality control.
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This page explains published research in plain language. It is not medical advice, a diagnosis, or a recommendation to take anything, and it does not give dosing. Most peptides here are not FDA-approved, and products sold online vary widely in purity. Rules around peptides are changing, so check the current status and talk with a licensed clinician before starting anything. Last reviewed 2026-10-19.