PIP: It is estimated that at the current rate of growth the world's population will reach 8.5 billion by the year 2025 and 10-11 billion by the end of the 21st century. 90% of this population increase would occur in developing countries, where only 38% of couples used contraceptives during 1980-81 compared to 68% in developed countries. About 300 million couples in the Third World do not use contraceptives, although they do not want more children. Some of these contraceptives include natural steroids, such as progesterone and 17 beta-estradiol that is used for treatment of menopause (1-2 mg daily po). Medroxyprogesterone acetate and norethisterone enanthate depot injections have long-acting properties with low failure rates (3.6% + 0.7 pregnancies/100 women years) if given every 3 months, amenorrhea may occur. RU-486, substance with antiprogesterone activity, inhibits hormonal metabolism during ovulation in a dose of 100 mg/day, just like norgestimate. HRP 102 consists of 50 mg norethisterone enanthate and 5 mg estradiol valerate and cycloprovera contains 25 mg medroxyprogesterone acetate with 5 mg of estradiol cypionate. Both of these agents are effective contraceptives for 2 months. Norplant is implanted subcutaneously in capsule forms. It releases levonorgestrel/LNG for 6-7 years, and in a study of 992 women 2.6 pregnancies occurred for 100 women in the course of 5 years. Vaginal suppositories can release 20 mg/day LNG, or 5-10 mg progesterone/day, and they are considered ideal for nursing mothers. The IUD has been used by 60 million women, however, pelvic inflammatory disease may be associated with its use. Sulprostone and RU-486 (mifepristone) are post ovulatory agents with effectiveness of up to 90 day. Female sterilization has problems of reversibility, male sterilization is less accepted, and other male endocrine approaches producing azoospermia are in the testing phase. The ideal contraceptive with properties of wide acceptability, reversibility, and effectiveness is yet to come.