Research

Hormonal

Combined blockade of GDF8 (myostatin) and Activin A using monoclonal antibodies significantly increases lean muscle mass and decreases fat mass in postmenopausal women, with effects reversing to baseline upon cessation of treatment.

For postmenopausal women seeking to increase muscle mass, blocking both myostatin and activin A via antibody therapy produces significant muscle growth and fat loss. However, this effect is not permanent; stopping treatment leads to a return to baseline muscle size within about 6 months. The treatment requires regular IV infusions and carries mild side effects like muscle spasms. It is not a lifestyle intervention but a medical therapy requiring clinical supervision.

ModerateSupportsMEDIUM confidence
Combining GDF8 and ActA blocking antibodies led to greater muscle growth than either antibody alone; increases in muscle were accompanied by reductions in fat... The combination was generally well tolerated... These results suggest that GDF8 and ActA are the dominant negative regulators of muscle mass in humans, and that combined blockade may be a promising therapeutic approach in muscle atrophy and obesity settings.
Dinko González Trotter et al. · Nature Communications · 2025

Why this rating

Phase 1 clinical trial in a small, specific population (n=82, postmenopausal women only for combination), focusing on safety and pharmacodynamics rather than long-term efficacy.

Source

GDF8 and activin A are the key negative regulators of muscle mass in postmenopausal females: a randomized phase I trial

Dinko González Trotter et al. · Nature Communications · 2025

DOI 10.1038/s41467-025-59380-3

rct · n=82Cited 13×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →