Muscle & Performance

A natural protein that blocks myostatin and activin, studied largely through gene therapy for muscle growth and muscular dystrophy.

A pegylated version of an IGF-1 splice variant studied in animals for muscle repair and satellite cell activation after damage.

A myostatin/activin decoy studied for muscular dystrophy whose trials were halted over vascular safety signals.

An amino-acid-derived compound essential for fat metabolism, FDA-approved for genuine deficiency and widely used for energy and recovery.

An antibody against latent myostatin, under FDA review for spinal muscular atrophy (decision due September 30, 2026) and shown to preserve 55% of the lean mass otherwise lost on tirzepatide.

Regeneron's anti-myostatin antibody, alone or with the anti-activin antibody garetosmab, preserved 51% to 81% of lean mass during semaglutide weight loss in the COURAGE trial, at the cost of more adverse events.

Biohaven's anti-myostatin/activin fusion protein being tested as a standalone weight-loss drug, with a Phase 2 obesity readout expected in the second half of 2026.

The selective androgen receptor modulator known on the gray market as ostarine, now in formal trials where 3 mg cut lean-mass loss on semaglutide by 71% in adults over 60.

Scholar Rock's follow-on to apitegromab, engineered for self-injection alongside GLP-1 drugs; Phase 1 readout expected in the second half of 2026.

A gray-market recombinant follistatin fragment marketed since late 2025 as a myostatin trap that builds muscle; there are no published studies, no pharmacokinetics and no safety data on the molecule itself.

A 24 amino acid fragment of a load-induced IGF-1 splice variant, sold for local muscle repair; in-vitro and animal data only, with at least one failed replication and a half-life of minutes.

IGF-1 missing its first three amino acids, which stops binding proteins from holding it and makes it roughly ten times more potent but cleared in minutes; in-vitro and animal data only.

The original 'exercise in a pill' from a 2008 Cell paper, an AMPK activator banned by WADA since 2009; human programs in heart surgery and leukemia failed to produce an approved drug, and effective animal doses are impractically large.