Is retatrutide FDA approved?

No. Retatrutide is investigational. As of this page's review date it has published phase 2 data and is in phase 3 trials, with no FDA approval for any indication.

How is retatrutide different from tirzepatide?

It adds glucagon receptor agonism to the GIP and GLP-1 activity that tirzepatide has. Whether that translates into a durable advantage is a phase 3 question, and phase 3 results are not published.

What is the half-life of retatrutide?

No published human pharmacokinetic study has been verified against a primary source for this page, so no half-life figure is stated here.

Retatrutide: what the evidence actually shows

Retatrutide is an investigational triple agonist of the GIP, GLP-1 and glucagon receptors, studied as a once-weekly subcutaneous injection.

Also known as LY3437943, reta.

Evidence and regulatory status

In registered human trials. Not approved for this use.

Investigational. Not approved by the FDA for any indication. Any material sold outside a clinical trial is unapproved.

Half-life

A half-life figure for Retatrutide has not been verified against a primary source for this page, so none is stated. The sources below are where a figure would come from.

What published trials used

The phase 2 obesity trial randomised participants to 1mg, 4mg, 8mg and 12mg once weekly against placebo over 48 weeks.

Reported for reference only. What a trial administered under supervision is not a recommendation, and Gireta does not make one.

How much research exists

PubMed records: 178
Tagged human: 107
Clinical trials: 7

A PubMed search for Retatrutide returns 178 records, of which 107 are tagged as human research and 7 are typed as a clinical trial.

Counted on 2026-09-04. Counts drift, so the exact query is linked rather than described, and you can re-run it.

Common questions

Is retatrutide FDA approved?: No. Retatrutide is investigational. As of this page's review date it has published phase 2 data and is in phase 3 trials, with no FDA approval for any indication.
How is retatrutide different from tirzepatide?: It adds glucagon receptor agonism to the GIP and GLP-1 activity that tirzepatide has. Whether that translates into a durable advantage is a phase 3 question, and phase 3 results are not published.
What is the half-life of retatrutide?: No published human pharmacokinetic study has been verified against a primary source for this page, so no half-life figure is stated here.

Sources

Retatrutide phase 2 · New England Journal of Medicine, via PubMed, 2023

Related compounds

Incretin receptor agonists

Act on the GLP-1 receptor, and in some cases on the GIP and glucagon receptors as well.

Tirzepatide Tirzepatide is a dual GIP and GLP-1 receptor agonist administered as a once-weekly subcutaneous injection.
Semaglutide Semaglutide is a GLP-1 receptor agonist available as a once-weekly subcutaneous injection and as a daily oral tablet.

Planning a schedule?

Gireta turns a compound and a cadence into a twelve-week timeline with the reconstitution maths worked out and a monthly cost.

Plan a Retatrutide schedule

Last reviewed 2026-09-04.