Is Azithromycin and roxithromycin legal in the United States?

Two approved macrolide antibiotics that removed roughly 97 percent of senescent human fibroblasts in one screening assay, while their close relative erythromycin did nothing. That is a single in vitro paper from a laboratory with a disclosed commercial interest, and the largest randomised trial of long-term azithromycin in people was stopped early for excess deaths.

The senolytic claim for these two antibiotics rests on one paper, published in Aging in 2018 by a group at the University of Salford. They used a screening assay to look for approved antibiotics that would preferentially kill senescent cells.

Mechanism: Both drugs are macrolide antibiotics that bind the bacterial 50S ribosomal subunit and block protein synthesis, which is what they are licensed to do. The proposed senolytic mechanism is unrelated to that.

Regulatory history: Azithromycin is FDA-approved as an antibiotic (Zithromax and generics). Roxithromycin is not marketed in the United States but is approved in the United Kingdom, Australia and many other countries. Neither is approved, or in any registered trial, for senescence, ageing or longevity.

Approves prescription drugs by indication and polices unapproved products, including peptides sold online. Compounding pharmacies may prepare some compounds under a prescription when the FDA places them on a permitted bulk-substances category.

The classification above is the The Longevity Archive reading of U.S. Food and Drug Administration listings for Azithromycin and roxithromycin 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.