Pharmacodynamics<unk>  is an agonist of the AR, the biological target of androgens like testosterone and . Unlike testosterone and certain other AAS,<unk>  is not potentiated in androgenic tissues like the scalp, skin, and prostate, hence deleterious effects in these tissues are lessened. This is because<unk>  is metabolized by 5α-reductase to the much weaker AR ligand 5α-dihydronandrolone (DHN), which has both reduced affinity for the androgen receptor (AR) relative to<unk>  in vitro and weaker AR agonistic potency in vivo. The lack of alkylation on the 17α-carbon drastically reduces the hepatotoxic potential of<unk> . Estrogen effects resulting from reaction with aromatase are also reduced due to lessened enzyme interaction, but effects such as gynecomastia and reduced libido may still occur at sufficiently high doses. In addition to its AR agonistic activity, unlike many other AAS,<unk>  is also a potent progestogen. It binds to the progesterone receptor with approximately 22% of the affinity of progesterone. The progestogenic activity of<unk>  serves to augment its antigonadotropic effects, as antigonadotropic action is a known property of progestogens. Anabolic and androgenic activity<unk>  has a very high ratio of anabolic to androgenic activity. In fact,<unk> -like AAS like<unk>  itself and trenbolone are said to have among the highest ratio of anabolic to androgenic effect of all AAS. This is attributed to the fact that whereas testosterone is potentiated via conversion into dihydrotestosterone (DHT) in androgenic tissues, the opposite is true with<unk>  and similar AAS (i.e., other 19-nortestosterone derivatives). As such,<unk> -like AAS, namely<unk>  esters, are the most frequently used AAS in clinical settings in which anabolic effects are desired; for instance, in the treatment of AIDS-associated cachexia, severe burns, and chronic obstructive pulmonary disease. However, AAS with a very high ratio of anabolic to androgenic action like<unk>  still have significant androgenic effects and can produce symptoms of masculinization like hirsutism and voice deepening in women and children with extended use. Pharmacokinetics The oral activity of<unk>  has been studied. With oral administration of<unk>  in rodents, it had about one-tenth of the potency of subcutaneous injection of<unk> .<unk>  has very low affinity for human serum sex hormone-binding globulin (SHBG), about 5% of that of testosterone and 1% of that of DHT. It is metabolized by the enzyme 5α-reductase, among others.<unk>  is less susceptible to metabolism by 5α-reductase and 17β-hydroxysteroid dehydrogenase than testosterone. This results in it being transformed less in so-called "androgenic" tissues like the skin, hair follicles, and prostate gland and in the kidneys, respectively. Metabolites of<unk>  include 5α-dihydronandrolone, 19-norandrosterone, and 19-noretiocholanolone, and these metabolites may be detected in urine. Single intramuscular injections of 100 mg<unk>  phenylpropionate or<unk>  decanoate have been found to produce an anabolic effect for 10 to 14 days and 20 to 25 days, respectively. Conversely, unesterified<unk>  has been used by intramuscular injection once daily.
Nandrolone
Oxandrolone
Norethandrolone
Androstanolone
Gestrinone
Norbormide
Androstanolone benzoate
Allenestrol