After their introduction in the 1960s, it was noticed that women on OCPs were developing blood clots in their legs and having heart attacks and strokes at higher rates. Newer generations of OCPs came with reduced doses of hormones, which lessened the risks.

So at this point in OCP history, how safe and effective are these pills? For non-smoking women age 15-30, there is no increase in death rate for a comparable form of contraception, the IUD. Because of the health risks of pregnancy, the death rate amongst women from age 15-34 who are on the pill is actually lower than for women who do not use any form of birth control.

OCPs can be unsafe in older women smokers. They should not be used in women with a history of blood clots, untreated high blood pressure, breast or uterine cancer, migraine headaches with focal neurological symptoms, known pregnancy, liver or cardiac disease. The same side effects women experienced with early pills are still a problem for some women taking modern versions: headaches, nausea, bloating, breast tenderness, and weight gain. Your OCP should have low estradiol (less than 50 µg) to decrease the risk of blood clotting.

For young, non-smoking women without hypertension or diabetes the health benefits balance the health risks of OCPs. For these women there is no increased risk of heart attack or stroke. There is a 28% increased risk of blood clot in the leg, but since this is rare the risk than any one particular woman will get one from an OCP is still very rare. For smokers there is an increased risk with OCPs that gets worse with age. For instance, the risk of death is 1 in 200,000 per year in non-smoking women under the age of 35. However risk increases with age and smoking to 1 in 700 per year for smokers over age 35.

The risk of cervical cancer doubles after 10 years of oral contraceptive therapy in women with a history of human papilloma virus infection (HPV). It is not clear if the risk is from the OCP or the increased risk of being infected with HPV for women on OCPs who may not use barrier protection. However since the risk of getting cervical cancer is .008% in any given year a doubling of risk means increasing your risk by another .008% per year. OCPs increase the risk of liver cancer. Liver cancer, however, is rare. OCPs increase the risk of breast cancer by 10-20%.

In women of childbearing age breast cancer is rare, and any increased risk and goes away after OCPs are stopped. In addition the types of breast cancers that develop in women on OCPs are more easily treatable; therefore the overall risk from breast cancer is not increased. OCPs reduce the risks of ovarian and uterine (endometrial) cancers. OCPs reduce the risk of anemia, through reduction of iron loss in menses, pelvic inflammatory disease, and osteoporosis (since estrogen promotes the laying down of calcium in the bones).

Women who take the pill have identical fertility rates after going off the pill compared to women who never took the pill. OCPs are safe for teenage girls to use, with the exception of Depo-Provera.

Use an OCP with low doses of estradiol (less than 50 µg). Taking an OCP is safe for women who don't smoke. For women who are smokers over age 35, or have other reasons not to take the regular pill (e.g. history of blood clots), consider the Minipill or another all progesterone pill, or one of the alternatives to the pill.