Is GYM329 legal in the United Kingdom?

The one myostatin antibody now being tested where it matters most: alongside tirzepatide in people with obesity, and for insulin sensitivity in type 2 diabetes. No results yet.

Three anti-myostatin antibodies added lean mass and failed to improve function, all in people with muscular dystrophy or long-standing weakness. GYM329 is the first to be aimed squarely at the population this site's readers belong to, and that makes it the most consequential open question in the field.

Mechanism: An antibody engineered by Chugai and Roche against latent myostatin, the inactive precursor form, rather than the mature active protein. It uses antigen sweeping, an engineering approach that promotes uptake and degradation of the antibody-antigen complex so the target is actively cleared instead of merely blocked.

Regulatory history: Investigational. Not approved for any indication.

Licenses medicines for the UK market. A compound without a marketing authorisation is an unlicensed medicine, which can only lawfully be supplied for human use through a prescriber under the specials scheme, not sold as a research product.

The classification above is the The Longevity Archive reading of Medicines and Healthcare products Regulatory Agency listings for GYM329 at the reviewed date, not a legal opinion. Rules change, and importing, prescribing and possessing a compound can each be treated differently. Check the regulator directly before acting on anything here.