Testosterone therapy efficacy

Orengo CA, Fullerton L, Kunik ME. Safety and efficacy of testosterone gel 1% augmentation in depressed men with partial response to antidepressant therapy. J Geriat Psychiatry Neurol 2005 18 20-4. 

The interest in pharmacological therapy for male pattern hair loss started as early as 1965, when a topieal preparation of testosterone was tested for presumed benefits. Topical testosterone failed to show any efficacy (86). The interest then declined until reports about stimulation of hair growth in hypertensive patients being treated with the then experimental drug minoxidil renewed the hopes. 

Poly(dimethylsiloxane) has been used to deliver steroid hormones to animals since the 1960 s and commercial poly-(dimethylsiloxane) based delivery systems for estradiol and progestins are currently available. Studies were conducted with androgens to develop poly(dimethylsiloxane) delivery systems that would maintain relatively constant blood testosterone concentrations in ruminant females for six months. All androgens tested passed through the poly(dimethylsiloxane) in vivo at rates proportional to surface area and increased blood testosterone concentrations relatively proportionally to the secretion rate. Implants with testosterone propionate incorporated in poly(dimethylsiloxane) (1) maintained relatively constant blood testosterone concentrations in vivo for six months and maintained more constant blood testosterone concentrations than commercially available implants (nonpoly (dimethylsiloxane) containing testosterone propionate, (2) evoked an anabolic effect in heifers, (3) maintained male sexual behavior in female ruminants and (4) prenatally andro-genized female ruminants. The poly(dimethylsiloxane) implants not only facilitated therapy but also enhanced efficacy and in some cases eliminated side effects. 

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