The steroid 19-nortestosterone (nandrolone, 19-NT), popularized in esterified form as nandrolone decanoate (ND, Deca-durabolin or simply “Deca”), is an injectable synthetic anabolic-androgenic steroid (AAS) used in the strength and fitness community for building muscle. The traditional stack, hailed by “bro science” for over 40 years, combines ND with a testosterone ester such as testosterone cypionate or testosterone enanthate. The objective of the combination is to maximize the anabolic effects while keeping the adverse effects of supraphysiological use in check. ND and its relative safety as an anabolic agent has been addressed in the clinical context (48, 49) and for non-medical (i.e., athletic performance or cosmetic) use (see, e.g., past