Once-a-month estrogen/progestogen injectables.

About 8 million women use the long acting injectable contraceptive depot-medroxy-progesterone acetate (DMPA) and norethisterone enanthate (NET-EN). These progesterone only injectables are not dependent on sexual activity and are easy to administer. Yet they are not always well accepted since they can interfere with menstrual bleeding and often induce amenorrhea. Researchers find that adding estrogen to DMPA and NET-EN treats these irregularities. They must use esters with limited action to protect the endometrium from constant estrogens, however, which requires monthly injections. Thus bleeding occurs once a month just like the normal menstrual cycle. Clinical trials in China of Injectable No. 1 (250 mg 17-alpha-hydroxyprogesterone caproate and 5 mg estradiol valerate) show that it has few side effects and is acceptable. Other trials in China are evaluating monthly injectables with NET-EN or megestrol acetate. Numerous developing countries often as WHO's Special Programme of Research in Human Reproduction for effective, safe, and fully studied monthly injectables. WHO operates under a 2 part strategy: optimum improvement of HPR 102 (50 m NET-EN and 5 mg estradiol valerate) and Cyclofem (25 mg DMPA and 5 mg estradiol cypionate) resulting in a reduction of the dose of at least 1 of the hormones and results of a study of the efficacy and side effects of these 2 injectables. It hopes the study provides the impetus to introduce them into national family planning programs. It demonstrates that they are indeed efficacious, effect fewer changes in the menstrual cycle than the progesterone only injectables, and are well accepted, even though women must go to a clinic every 27-33 days for an injection. Other studies are determining their effects on lipid and glucose metabolism, coagulation, and fibrinolysis. They are also looking at the time needed for ovulation to return. 1 study shows that menstruation returned in all women by the 3rd cycle.