An oral contraceptive is a hormonal form of birth control that is taken by mouth in pill form, also known as the birth control pill, or simply "the Pill". This form of birth control uses hormones that naturally occur in a woman's body to manipulate the functioning of the reproductive system and prevent pregnancy. Several different formulations and dosing schedules are available, and the pills are sold under many brand names. Oral contraceptive use is usually extremely effective at preventing pregnancy when dosage instructions are followed accurately. There are a variety of common side effects and some risks associated with prolonged use.
There are many different formulations of oral contraceptive sold under numerous brand names. Some pills have the same dosage of hormones on each day, and others vary the dosage according to the phase of a woman's menstrual cycle. The pills may be taken on a 21-day schedule, with no pill taken for the other seven days, or on a 28-day schedule with placebo pills taken on the last seven days of the cycle, to allow menstruation to occur. Another dosing schedule that is gaining popularity is to take active pills with hormones on all days of the cycle, preventing menstruation from occurring, or limiting it to a few times per year.
Oral contraceptive use is estimated to be over 99 percent effective in preventing pregnancy when taken according to directions. Directions vary according to the brand, but generally include taking the pill at the same time of day each day, and not skipping any active dose. If a dose is missed, a back-up form of birth control needs to be used. Sometimes oral contraceptive use is prescribed for reasons other than preventing pregnancy, such as the treatment of abnormally heavy or irregular menstrual bleeding, endometriosis, and acne.
Before beginning oral contraceptive use, a woman should discuss her complete medical history including any medications or supplements she may be taking, with her doctor, to avoid possible complications or drug interactions. Common side effects include weight gain, breast tenderness, nausea, mood changes, headache, and irregular bleeding. More serious side effects such as severe depression, chest pain, shortness of breath, sudden severe headache, or groin or calf pain should be reported to a doctor immediately. Some risks of use include heart attack, stroke, blood clots, and elevated blood pressure, particularly if the user smokes and is over 35. Prolonged use of oral contraceptives may also be associated with an increased risk for breast or liver cancer.
