Volunteers with normal and subnormal semen parameters receive a hormonal male contraceptive in order to investigate whether there are differences between normal and subnormal men in terms of suppressibility, rate of azoospermia and reversibility of suppression of spermatogenesis. Twenty-five men will be recruited for each group. They will be exposed to hormonal male contraception for six months.
Volunteers with normal and subnormal semen parameters receive a hormonal male contraceptive in order to investigate whether there are differences between normal and subnormal men in terms of suppressibility, rate of azoospermia and reversibility of suppression of spermatogenesis.