The use of testosterone in sports practice is common concomitantly with clomiphene and growth hormone, which induce endogenous testosterone production, reducing testicular atrophy [9,20]; combined with tamoxifen, an anti-estrogen substance, to block gynecomastia symptoms [9,20], and with sildenafil or tadalafil (phosphodiesterase type 5 inhibitors) to erectile dysfunction treatment [9], and finasteride (5-alpha reductase inhibitors) for treating alopecia [9]. The gene discussed is GH1; the disease is alopecia.