The potential for testosterone transfer from healthy males dosed with FORTESTA to healthy females was evaluated in a placebo-controlled, three-way crossover study . The washout period was approximately 29 days. Six males were treated with either FORTESTA (30 mg testosterone) or placebo to one thigh only. At 2 hours after the application of FORTESTA to males, the females rubbed their forearms for 15 minutes on the thigh of the males. Serum concentrations of testosterone were monitored in females for 24 hours after the transfer procedure. When direct skin-to-skin transfer occurred with FORTESTA mean Cavg increased by 134% and mean Cmax increased by 191%, compared to direct skinto- skin transfer with placebo. When transfer occurred with FORTESTA while covering a thigh with boxer shorts, mean Cavg decreased by 3% and mean Cmax increased by 2%, compared to direct skin-toskin transfer with placebo [see DOSAGE AND ADMINISTRATION ].
The second theory is similar and is known as "evolutionary neuroandrogenic (ENA) theory of male aggression".   Testosterone and other androgens have evolved to masculinize a brain in order to be competitive even to the point of risking harm to the person and others. By doing so, individuals with masculinized brains as a result of pre-natal and adult life testosterone and androgens enhance their resource acquiring abilities in order to survive, attract and copulate with mates as much as possible.  The masculinization of the brain is not just mediated by testosterone levels at the adult stage, but also testosterone exposure in the womb as a fetus. Higher pre-natal testosterone indicated by a low digit ratio as well as adult testosterone levels increased risk of fouls or aggression among male players in a soccer game.  Studies have also found higher pre-natal testosterone or lower digit ratio to be correlated with higher aggression in males.