Contraceptive pills side effects

The most common side effect is breakthrough bleeding. The majority (about 60%) of women report no side effects at all, and the vast majority of those who do, have only minor effects.

Combined oral contraceptives may influence coagulation, increasing the risk of deep venous thrombosis (DVT) and pulmonary embolism, stroke and myocardial infarction (heart attack). Combined oral contraceptives are generally accepted to be contraindicated in women with pre-existing cardiovascular disease, in women who have a familial tendency to form blood clots (such as familial factor V Leiden), women with severe obesity and/or hypercholesterolemia (high cholesterol level), and in smokers over age 40.
Combined oral contraceptives are also contraindicated for women with liver tumors, hepatic adenoma or severe cirrhosis of the liver, and for those with known or suspected breast cancer.
Combined oral contraceptives decrease the risk of ovarian cancer, endometrial cancer, and colorectal cancer.
The use of oral contraceptives (birth control pills) for five years or more decreases the risk of ovarian cancer in later life by 50%. Combined oral contraceptive use reduces the risk of ovarian cancer by 40% and the risk of endometrial cancer by 50% compared to never users. The risk reduction increases with duration of use, with an 80% reduction in risk for both ovarian and endometrial cancer with use for more than 10 years. The risk reduction for both ovarian and endometrial cancer persists for at least 20 years.

Taking oral contraceptives also reduces the risk of colorectal cancer, and improves conditions such as pelvic inflammatory disease, dysmenorrhea, premenstrual syndrome, and acne. Additionally, birth control pills reduce symptoms of endometriosis and polycystic ovary syndrome, and decrease the risk of anemia.

It is generally accepted by medical authorities that the health risks of oral contraceptives are lower than those from pregnancy and birth, and “the health benefits of any method of contraception are far greater than any risks from the method”.