Semaglutide Trials Reveal Less Muscle Loss with Antibody Combo; Hormonal Contraception Increases Use

In the BELIEVE phase‑2 trial, 507 adults with obesity were randomized to semaglutide, bimagrumab, or their combination. Adding the muscle‑targeting antibody bimagrumab to semaglutide reduced lean‑mass loss from 7.4 % to 2.9 % over 72 weeks and produced greater total weight loss—up to 22.1 % of body weight, with about 70 % of participants achieving at least a 20 % reduction.

A separate nested case‑control study using Danish register data examined 22,694 women aged 12‑49 who started semaglutide for weight management. Women who had used hormonal contraception were more likely to initiate semaglutide, with adjusted hazard ratios ranging from 1.42 for combined oral pills to 2.11 for certain contraceptive patterns, a relationship that persisted across age, education, income, parity, immigrant status, and semaglutide type sub‑analyses.