Drug Research Information Bulletin - The Safety of 17α-Methyltestosterone Administered in Feed to Larval Nile Tilapia

Orally administered 17MT is an efficacious, cost-effective, and efficient way to produce predominantly male populations of tilapia. However, its use in the U.S. for tilapia production depends on its approval by the U.S. Food and Drug Administration (FDA). Approval by FDA requires, in part, that studies be conducted to demonstrate the proposed treatment regimen is safe to target animals. As such, we conducted a study to estimate a margin of safety associated with administering 17MT-treated feed to larval Nile tilapia O. niloticus (mean weight at start of study, 0.032 g) at 0, 9, 27, or 45 mg 17MTper kg fish body weight per d (equivalent to 0×, 1×, 3×, or 5× the proposed maximum efficacious dosage of 9 mg 17MT per kg fish body weight per d) for 28 consecutive days.