Studies have been undertaken of sex offenders who have been given chemical agents capable of suppressing testosterone. A number of studies suggest that such chemicals can reduce the number and intensity of sexual fantasies and episodes of deviant behaviour. Associated claims of reduced reoffending and violence have been made, but these rates have not been compared with rates for similar men not so treated. What we do know is that the great majority of men who sexually abuse and molest women and children do not manifest any consistent, reliable and significant abnormalities in testosterone secretion or levels. Something else is at work.
Males have more testosterone in their circulation than females and men are more aggressive.
Women do produce testosterone and men do produce oestrogen. The normal woman produces about 200 micrograms of testosterone and 120 micrograms of oestrogen each day, a ratio of about 1.6 to 1. Deprived of testosterone, men appear to lose the desire for sex. But the relationship between testosterone and the penis is very complex. Spontaneous erections, such as those that occur in the night, are highly dependent on the level of circulating testosterone.