4-AZA-5-ALPHA-ANDROST-1-EN-3-ONES AND PHARMACEUTICAL COMPOSITIONS

17 beta -N-monosubstituted carbamoyl or 17 beta -acyl-4-aza-5 alpha -androst-1-en-3-ones of the formula: in which R is hydrogen, methyl or ethyl; R is a C1-12 straight or branched alkyl radical or a monocyclic aryl optionally containing one or more methyl or ethyl substituents and/or one or more Cl, F or Br substituents; and in Formula IA R may also be benzyl, phenethyl, 2-pyridyl, 4-pyridyl, 2-pyrrolyl, 2-furyl or thiophenyl; R min is hydrogen or methyl; R sec is hydrogen or beta -methyl and in Formula IA may also be alpha -methyl; and R''' is hydrogen, alpha -methyl or beta -methyl and pharmaceutical formulations containing the above compounds are active as testosterone 5 alpha -reductase inhibitors and thus are useful topically for treatment of acne, seborrhoea and female hirsutism, and systemically in the treatment of benign prostatic hypertrophy.