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Hormonal Contraception/Birth Control
What is it?
Hormonal contraception is one approach to birth control. It may be accomplished through various methods, which all involve interference with normal sex hormone function in the body. Hormonal contraception for men is under study, but existing hormonal contraception is used almost exclusively by women. Currently-available hormonal contraceptives disrupt the normal menstrual cycle by altering the levels of the female hormones, mainly estrogen and/or progesterone. By changing the amounts of estrogen, progesterone, or both; hormonal contraceptives interfere with the release, fertilization, and/or implantation of human eggs.
Combination contraceptives contain both a synthetic estrogen (usually one known as ethinyl estradiol) and any one of several progestins (synthetic progesterones). Typically, they are taken or used for 3 weeks per month ? usually being discontinued during the week of the menstrual period. Among the general types of hormonal contraceptives that contain both an estrogen and a progestin are:
Combined oral contraceptive pills (COCs - also known as birth-control pills, OCs, or the ?pill?) ? Usually packaged in a compact-like case that holds a one-month supply (either 21 pills that contain active hormones or 21 active pills and 7 inactive placebo ?sugar pills?), COCs may be:
- monophasic (all the pills contain the same amounts of both estrogen and progestin)
- biphasic (two different dose levels of the hormones are taken during separate parts of the menstrual cycle)
- triphasic (three different amounts of hormones are used in an effort to better match the normal menstrual cycle and minimize side effects)
Contraceptive patches ? adhesive bandage-like squares that stick to the skin and release hormones for one week
Injectable estrogen and progestin combinations (no longer available in the US) ? continuous hormone release from once-monthly injections
Vaginal rings ? soft circles of vinyl that are saturated with estrogen and a progestin. Inserted once a month into the vagina, they release hormones for 3 weeks before being removed.
Progestin-only contraceptives work mainly by keeping sperm from reaching an egg. They include the following kinds of products:
Injectable progestins ? usually oil-based products that release a progestin gradually over one to 3 months after a single injection
Intrauterine devices (IUDs) ? certain brands contain reserves of a
progestin that releases slowly as long as the IUD is in place
Progestin-only pills (also called POPs or ?minipills?) ? tablets taken orally every day
Progestin implants (not currently available in the United States) ? progestin-filled rubber or plastic tubes that release a progestin slowly for much longer times (up to 5 years) after being inserted under the skin
For information on the benefits and risks of each hormonal contraceptive method, click on the links below.
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What is it?
