Dimethandrolone Undecanoate
Novel investigational compound under active clinical development (NIH/Los Angeles Biomedical Research Institute) as a once-daily oral male contraceptive. Uniquely combines androgenic and progestogenic activity — meaning a single agent can fully suppress spermatogenesis without requiring a progestin co-agent. Not available outside clinical trials.
Mechanism of Action
11β-methyl-19-nortestosterone undecanoate. Potent AR and progesterone receptor (PR) agonist. Complete azoospermia achieved via dual AR + PR-mediated LH/FSH suppression in all Phase I subjects. No aromatization. No 5α-reduction to a more active metabolite. Oral bioavailability improved by undecanoate ester and fat absorption.
Typical Dosing
⚠ Warning Flags
- •Investigational only — not approved; not available outside clinical trials
- •Long-term human safety data not yet established
Effect Profile
Side Effect Profile
Research Studies
Dimethandrolone undecanoate shows promise as a male oral contraceptive agent
Ayoub R, et al. · 2017
Phase I clinical trial: 28-day oral DMAU at 400 mg/day significantly suppressed LH, FSH, and testosterone in all subjects, with no serious adverse events — the most promising oral male contraceptive candidate to date.
Daily oral dimethandrolone undecanoate in men: pharmacokinetics and reversibility of suppression of the hypothalamic-pituitary-testicular axis
Thirumalai A, et al. · 2019
Extended 28-day study confirmed DMAU's complete and reversible gonadal suppression; serum testosterone recovered to normal within 90 days of cessation, demonstrating reversibility important for contraceptive use.