- Reliable barrier methods include condoms and diaphragms. A cervical cap is also a reliable barrier method, provided that the female subject has never given birth naturally. The combined use of a condom and spermicide constitute 2 forms of acceptable nonhormonal contraception, provided that they are both used properly. The use of spermicide alone and the improper use of condoms are inferior methods of contraception. Subjects with surgical sterilization, including tubal ligation or partner's vasectomy, must use a form of nonhormonal contraception. A barrier method or sterilization plus spermatocide are acceptable.