Retatrutide: what it is, what the studies show and where it stands
Retatrutide is an agonist of the glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1 and glucagon receptors, studied as a once-weekly injection for obesity.
At a glance
US Not approved, in trials
Canada Not authorized
Group Weight loss and metabolic
Sources 3
Checked 10 Oct 2026What is Retatrutide?
Retatrutide is an agonist of the glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1 and glucagon receptors, studied as a once-weekly injection for obesity. [1]
Other names: LY3437943.
How it has been given to people: subcutaneous injection, once weekly.
Looking for doses? Retatrutide dosage chart and vial math
Is Retatrutide approved in the US and Canada?
United States: Not FDA approved. Drugs@FDA has no retatrutide application, and FDA states that retatrutide is not a component of an FDA-approved drug and cannot be used in compounding.
Canada: No retatrutide product is in the Health Canada Drug Product Database. Health Canada lists retatrutide among unauthorized injectable peptide drugs it has seized.
Both were checked on 10 Oct 2026 against the regulators' own product databases.
Which approved products contain Retatrutide?
No approved medicine containing Retatrutide was found in the US or Canada. Anything sold under this name is not a regulated product, so there is no label to check a dose against.
What human studies of Retatrutide exist?
The 2 findings listed here: 2 from randomized human trials.
What are the side effects of Retatrutide?
Reported in human studies or on a label:
What is the half-life of Retatrutide?
About 6 days, from a 12-week phase 1b trial of once-weekly dosing in people with type 2 diabetes (72 enrolled). [3]
How does Retatrutide compare with others in its group?
These are the peptides filed under weight loss and metabolic. The last column says whether a randomized human trial is on record for each.
| Peptide | US | Canada | Half-life | Randomized human trial |
|---|---|---|---|---|
| Retatrutide | Not approved, in trials | Not authorized | About 6 days, from a 12-week phase 1b trial of once-weekly dosing in people with type 2 diabetes (72 enrolled). | Yes |
| Tirzepatide | Approved, prescription | Authorized, prescription | About 5 days. | Yes |
| Semaglutide | Approved, prescription | Authorized, prescription | About 1 week. | Yes |
| Cagrilintide | Not approved, in trials | Not authorized | 159 to 195 hours, about 6.6 to 8.1 days, measured in a phase 1b trial where it was given with semaglutide 2.4 mg. | Yes |
| AOD-9604 | Not approved | Not authorized | Not found | Yes |
| 5-Amino-1MQ | Not approved | Not authorized | Not found | No |
| SLU-PP-332 | Not approved | Not authorized | Not found | No |
| HGH Fragment 176-191 | Not approved | Not authorized | Not found | No |
What could not be found
These were searched for and did not turn up. They are listed so a missing number is not mistaken for a hidden one.
- No approved label, so no official contraindications, interaction list, missed-dose rule or storage instructions.
- A half-life figure from the phase 1 single ascending dose study. Its abstract (PMID 35985340) says only that the pharmacokinetic profile supported once-weekly dosing.
Retatrutide questions
Is Retatrutide approved in the US?
Not FDA approved. Drugs@FDA has no retatrutide application, and FDA states that retatrutide is not a component of an FDA-approved drug and cannot be used in compounding.
Is Retatrutide authorized in Canada?
No retatrutide product is in the Health Canada Drug Product Database. Health Canada lists retatrutide among unauthorized injectable peptide drugs it has seized.
What is the half-life of Retatrutide?
About 6 days, from a 12-week phase 1b trial of once-weekly dosing in people with type 2 diabetes (72 enrolled).
Has Retatrutide been tested in a randomized human trial?
Yes. At least one randomized human trial is listed on this page.
Sources
Each one was opened on 10 Oct 2026 and matched to the line it supports.
- Jastreboff AM et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial. N Engl J Med 2023. PubMed 37366315. Trial NCT04881760.
- Jastreboff AM et al. Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity. N Engl J Med 2026. PubMed 42814954. Trial NCT05929066.
- Urva S et al. LY3437943, a novel triple GIP, GLP-1, and glucagon receptor agonist in people with type 2 diabetes: a phase 1b, multicentre, double-blind, placebo-controlled, randomised, multiple-ascending dose trial. Lancet 2022. PubMed 36354040. Trial NCT04143802.
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Retatrutide dosage10 mg vial30 mg vialWeight loss and metabolicStatus in Canada
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