Bimagrumab and Semaglutide: What the BELIEVE Trial Found

Bimagrumab plus semaglutide has been tested in a randomized human obesity trial. In BELIEVE, the high-dose combination produced a mean 17.8 kg weight reduction at 48 weeks, compared with 14.2 kg for semaglutide alone. The combination is a research treatment, rather than a synonym for a semaglutide prescription.

The trial results in one table

The phase 2 study randomized 507 adults across nine groups. Bimagrumab was administered intravenously every 12 weeks; semaglutide was injected subcutaneously weekly. Treatment lasted 48 weeks, followed by an open-label extension to week 72.

What the comparison adds

Subtracting the reported means gives 3.6 kg more weight reduction for the high-dose combination than semaglutide alone. That calculation describes the trial averages. It does not identify how much of the difference was fat or muscle.

Weight and muscle are different measurements

Bimagrumab targets type II activin receptors. The study tests a body-composition approach alongside an incretin medicine. A scale measures total weight; a muscle-preservation claim needs body-composition and functional measurements, rather than weight alone.

Read the primary study

Heymsfield and colleagues, Nature Medicine, 2026 reports the BELIEVE trial, NCT05616013. The combination-versus-single-agent comparison is the useful evidence here; the two medicines were administered separately in the study.

Can this page replace medical advice about semaglutide?

No. Bimagrumab Semaglutide Combination is informational. A licensed clinician who knows your history should review contraindications, labs, medication fit, and dose decisions.