The proposed study will be conducted in men in order to evaluate the safety and contraceptive efficacy of Nestorone gel and testosterone gel, both applied transdermally, in couples who wish to avoid pregnancy and are willing to use the method as their primary method of birth control. Nestorone gel (progestogen) in addition to testosterone (T) gel (androgen), both applied transdermally, has been shown to suppress gonadotropins and sperm production. Preliminary results from these studies indicate that a dose of 8 mg of Nestorone gel is required in order to suppress gonadotropins sufficiently to a level that inhibits spermatogenesis. There are very few contraceptive options available to men. Studies indicate that men would use a safe and reversible method of contraception if one were available to them. One promising regimen involves a method of delivering androgen plus progestogen in order to suppress sperm production. The goal of this study is to conduct a clinical trial to test whether Nestorone and testosterone, both applied transdermally, will be effective for contraception in couples who are willing to use the method as their primary method of contraception. The proposed study will be conducted in men in order to evaluate the safety and contraceptive efficacy of Nestorone gel and testosterone gel.