Combined oral contraceptives, typically called "the pill," contain low doses of both estrogen and progestogen, which are similar to the hormones produced by the ovaries. These oral contraceptives are relatively safe and effective, and when used properly have over 99% success at preventing pregnancy. The most common reasons for the pill failing are skipping pills, illness (vomiting and diarrhea may impede absorption of the pill in your gut), and drug interactions (tell you doctor you're on the pill so s/he won't give you something that will decrease the pill's effectiveness). A version called the "minipill" contains only the hormone progestogen. It is a good option for women who can't take estrogen, because they are breast-feeding or because products with estrogen cause them to have severe headaches or high blood pressure, for example. Compared to combination oral contraceptives, the minipill has a slightly higher pregnancy rate in adolescents, because it has to be taken at the same time every day and that can be a bit of a burden for a teenager. In older women the efficacy of the minipill seems to be similar to that of the regular pill.

Besides preventing pregnancy, oral contraceptives have a number of other benefits. They can improve menstrual regularity, prevent ectopic pregnancy, and they seem to reduce the risk of endometrial and ovarian cancer. The pill can also reduce the risk of benign breast disease (but some believe it can increase the risk of breast cancer, although the jury is still out on that one), ovarian cysts, and pelvic inflammatory disease. The combination contraceptives can also be used to treat acne and excess body and facial hair (hirsutism) in women. And dare I mention, but it is possible that oral contraceptive use decreases the incidence of premenstrual syndrome (PMS). You heard it here.

In general, complications from the pill in young healthy women are rare. The major risks involved are cardiovascular, and include blood clots, heart attacks, and strokes. Women on the pill are more likely to develop blood clots (in their legs, especially) than those who do not use oral contraceptives. The risk of these clots is associated with estrogen, so those on the minipill are not so at risk. All women on the pill should know the symptoms that indicate a possible blood clot and contact a doctor immediately if these symptoms are felt: sharp pain in the chest, coughing blood, or sudden shortness of breath; pain in the calf; sudden partial or complete loss of vision. Now, women who do not smoke, who have their blood pressure checked and are in good health have very little if any increased risk of heart attack, and little increased risk of stroke when they use combined oral contraceptives. However, if you should happen to be on the pill and a smoker, especially an older woman, your risk for cardiovascular disease is substantial. Older women who are smokers should not get on the pill, but ask your doctor for the final say. Also, those who are pregnant, have or have had clotting disorders, have heart disease, breast cancer, liver tumors, diabetes, hypertension, or undiagnosed abnormal vaginal bleeding should not get on the pill.

I've tried to outline some of the major points to think about when considering the pill, but there's certainly much more, and the best way to know if the pill might work for you is by going to the doctor. I've listed reading below with good information for those who want to get a jump-start. For those on the pill already, be familiar with the warning signs for the major complications and be alert to any physical or mental change (i.e. depression) that may warrant a visit to the doctor.

I also want to remind you, like I've said before: the pill does not protect against STDs, and if you think your partner is at risk for having a sexually transmitted disease, USE A CONDOM. So if you're doing it, you can do it right.

For all the info, read:

• "Facts about Oral Contraceptives" at www.nih.gov/health/chip/nichd/oralcnt/
• "Benefits and risks of oral contraceptives" by Katherine Sherif, MD. In the June 1999 supplement to the American Journal of Obstetrics and Gynecology (for you scientific types).