---
title: "Retatrutide phase 2 (Jastreboff): Retatrutide Phase 2"
url: https://www.primaralabs.com/research/trials/retatrutide-phase-2
source: Primara Labs, markdown mirror of the HTML page
---

# Retatrutide phase 2 (Jastreboff)

In Retatrutide phase 2 (Jastreboff), a phase 2 trial of retatrutide in adults with a BMI of 30 or more, or 27 to under 30 with at least one weight-related condition (n=338), mean body weight fell 8.7% on 1 mg, 17.1% on 4 mg (pooled), 22.8% on 8 mg (pooled) and 24.2% on 12 mg over 48 weeks, against 2.1% on placebo (Jastreboff AM et al. N Engl J Med 2023;389:514-526).

Primara Labs sells some of the compounds covered here. Every figure on this page links to its source and the date it was checked.

Updated 24 September 2026

## Results

Mean percent change in body weight by arm, as each source reports it. Navy bars are the trial arms, grey bars the comparator. Bars from different trials are not a head-to-head comparison: populations, durations and estimands differ.

## Side effects reported

Retatrutide phase 2 (Jastreboff): The abstract reports gastrointestinal events as the most common, dose-related and mostly mild to moderate, without rates; rates by arm are in the full text, not read here.

Design

## Trial design and sources

Compound

Retatrutide

Phase

2

Population

Adults with a BMI of 30 or more, or 27 to under 30 with at least one weight-related condition

Participants randomised

338

Duration

48 weeks

Primary endpoint

Percent change in body weight from baseline at 24 weeks; 48 weeks secondary

Estimand

Not stated in the source read

Read out

26 June 2023

48-week figures (least-squares mean). At the 24-week primary endpoint the arms were -7.2%, -12.9%, -17.3% and -17.5% against -1.6% on placebo. The abstract reports gastrointestinal events as the most common, dose-related and mostly mild to moderate, without rates; rates by arm are in the full text, not read here.

-   Jastreboff AM et al. N Engl J Med 2023;389:514-526 [open](https://doi.org/10.1056/NEJMoa2301972) · checked 23 September 2026
-   ClinicalTrials.gov NCT04881760 [open](https://clinicaltrials.gov/study/NCT04881760) · checked 23 September 2026
-   Registry: NCT04881760

Questions

## Retatrutide phase 2 (Jastreboff), answered

### What did Retatrutide phase 2 (Jastreboff) find?

In Retatrutide phase 2 (Jastreboff), a phase 2 trial of retatrutide in adults with a BMI of 30 or more, or 27 to under 30 with at least one weight-related condition (n=338), mean body weight fell 8.7% on 1 mg, 17.1% on 4 mg (pooled), 22.8% on 8 mg (pooled) and 24.2% on 12 mg over 48 weeks, against 2.1% on placebo (Jastreboff AM et al. N Engl J Med 2023;389:514-526).

### What side effects were reported in Retatrutide phase 2 (Jastreboff)?

Retatrutide phase 2 (Jastreboff): The abstract reports gastrointestinal events as the most common, dose-related and mostly mild to moderate, without rates; rates by arm are in the full text, not read here.

Related

## More on retatrutide

-   [TRIUMPH-1](https://www.primaralabs.com/research/trials/triumph-1)
-   [TRIUMPH-2](https://www.primaralabs.com/research/trials/triumph-2)
-   [TRIUMPH-3](https://www.primaralabs.com/research/trials/triumph-3)
-   [TRIUMPH-4](https://www.primaralabs.com/research/trials/triumph-4)
-   [TRIUMPH-5](https://www.primaralabs.com/research/trials/triumph-5)
-   [TRIUMPH-6](https://www.primaralabs.com/research/trials/triumph-6)
-   [TRIUMPH-7](https://www.primaralabs.com/research/trials/triumph-7)
-   [TRIUMPH-8](https://www.primaralabs.com/research/trials/triumph-8)
-   [TRIUMPH-9](https://www.primaralabs.com/research/trials/triumph-9)
-   [TRIUMPH-OUTCOMES](https://www.primaralabs.com/research/trials/triumph-outcomes)
-   [Evidence Map: Retatrutide](https://www.primaralabs.com/research/evidence#retatrutide)
-   [Retatrutide 20mg](https://www.primaralabs.com/marketplace/retatrutide)