Dimethandrolone Undecanoate, a Novel, Nonaromatizable Androgen, Increases P1NP in Healthy Men Over 28 Days

Abstract

Abstract Context Dimethandrolone undecanoate (DMAU) is being developed as a male contraceptive. Daily oral administration of DMAU, a potent androgen that is not aromatized, markedly suppresses serum testosterone (T) and estradiol (E2) in healthy men. E2 deficiency can increase bone resorption in men. Objective This work aimed to assess changes in bone turnover markers with DMAU administration in a 28-day study. Design A randomized, double-blind, placebo-controlled study was conducted. Setting This study took place at 2 academic medical centers. Participants Healthy men, age 18 to50 years (n = 81), participated. Intervention Men received 0, 100, 200, or 400 mg of oral DMAU for 28 days. Serum C-terminal telopeptide of type I collagen (CTX; bone resorption marker) and procollagen type I amino-terminal propeptide (P1NP; bone formation marker) were measured on days 1 and 28. Main Outcome Measures Changes in bone turnover markers and serum hormones over the treatment period were measured. Results On day 28, median serum T and E2 were markedly suppressed in all treatment groups vs placebo (P < .001 for both). Percentage change (%) in serum P1NP significantly differed across treatment groups (P = .007): Serum P1NP significantly increased in the 200 mg (5%, interquartile range [IQR] –7% to 27%) and 400 mg (22%, IQR –1% to 40%) groups relative to placebo (–8%, IQR –20% to 0%). Change (%) in serum CTX did not differ between groups (P = .09). Conclusions DMAU administration for 28 days to healthy men leads to marked suppression of serum T and E2, yet increases P1NP, a serum marker of bone formation. Longer-term studies of the potent androgen DMAU are warranted to determine its impact on bone health in men.