Pharmacodynamics<unk>  binds to and activates the androgen receptor (AR) in order to exert its effects. These include dramatic increases in protein synthesis, glycogenolysis, and muscle strength over a short space of time. While it can be metabolized by 5α-reductase into methyl-1-testosterone (17α-methyl-δ1-DHT), a more potent AAS, the drug has extremely low affinity for this enzyme and methyl-1-testosterone is thus produced in only trace amounts. As such, 5α-reductase inhibitors like finasteride and dutasteride do not reduce the androgenic effects of<unk> . Nonetheless, while the ratio of anabolic to androgenic activity of<unk>  is improved relative to that of testosterone, the drug does still possess moderate androgenic activity and is capable of producing severe virilization in women and children. As such, it is only really commonly used in men.<unk>  is a substrate for aromatase and can be metabolized into the estrogen methylestradiol (17α-methylestradiol). While the rate of aromatization is reduced relative to that for testosterone or methyltestosterone, the estrogen produced is metabolism-resistant and hence<unk>  retains moderate estrogenic activity. As such, it can cause side effects such as gynecomastia and fluid retention. The co-administration of an antiestrogen such as an aromatase inhibitor like anastrozole or a selective estrogen receptor modulator like tamoxifen can reduce or prevent such estrogenic side effects.<unk>  has no progestogenic activity. As with other 17α-alkylated AAS,<unk>  is hepatotoxic. Pharmacokinetics<unk>  has high oral bioavailability. It has very low affinity for human serum sex hormone-binding globulin (SHBG), about 10% of that of testosterone and 2% of that of DHT. The drug is metabolized in the liver by 6β-hydroxylation, 3α- and 3β-oxidation, 5β-reduction, 17-epimerization, and conjugation among other reactions. Unlike methyltestosterone, owing to the presence of its C1(2) double bond,<unk>  does not produce 5α-reduced metabolites. The elimination half-life of<unk>  is about 3 to 6 hours. It is eliminated in the urine.
Metandienone
Amrinone
Nortilidine
Iofetamine 
Boldenone undecylenate
Colestilan
Verapamil
Amiodarone