Birth control is any activity, medicine, or equipment used to prevent pregnancy. There are many types of birth control available for people who do not wish to become pregnant. The decision on which method is right for you should be made with your doctor, as well as with your partner.

Birth control methods work in different ways to prevent pregnancy, including:

• Making a barrier that blocks sperm from reaching the egg
• Killing sperm
• Preventing eggs from being released by the ovaries
• Changing the cervical mucus to prevent sperm from moving into the uterus
• Altering the tissue lining of the uterus so that a fertilized egg can't implant

You don't need a prescription from your doctor for these methods:

• Abstinence. Not having sex.
• Spermicides. Foams or creams placed inside the vagina to kill sperm. These may also protect against sexually transmitted infections (STIs), especially when used with a latex condom.
• Male condom. A thin tube made of latex or a natural material that is placed over the penis. The sperm is collected in the end of the condom. Latex condoms may provide some protection against STIs.
• Female condom. A liner made of latex or natural material that is placed inside the vagina. Latex condoms may protect against STIs.
• Natural family planning. Timing sex to avoid fertile days using various ways of keeping track of body temperature. It also involves watching for changes in cervical mucus and using ovulation prediction kits. This method is often known as the rhythm method. It has a high risk for pregnancy.

You need to visit your doctor for an exam and a prescription for these methods:

• Birth control pills (oral contraceptives). Medicines taken daily that prevent ovulation by controlling pituitary hormone secretion. Usually, oral contraceptives contain the hormones estrogen and progestin. In addition to preventing pregnancy, oral contraceptives have some health benefits. They can regulate menstrual cycles and decrease the amount and length of menstrual periods. This can help increase iron stores in people with iron deficiency linked to excessive bleeding. Oral contraceptives can also prevent certain ovarian and endometrial cancers. Some research has found that some benign (noncancerous) breast diseases happen less often with the use of oral contraceptives. These breast diseases include fibroadenoma and cystic changes. Recent studies have also suggested that oral contraceptive use may reduce the occurrence of rheumatoid arthritis.
• Minipill. Daily medicine that has only the hormone progestin, unlike the traditional birth control pill. The minipill thickens cervical mucus and prevents the sperm from reaching the egg. It also can decrease the flow of your period and protect against pelvic inflammatory disease and ovarian and endometrial cancer.
• Implant. A capsule containing the synthetic hormone etonogestrel. It is put under the skin in the upper arm of a woman. It prevents the ovaries from releasing an egg for up to 3 years. A local anesthetic is needed for putting in and taking out this type of birth control.
• Injection. A progesterone-like medicine given by injection that stops ovulation. The effects last for about 3 months. Another injection must be given to continue birth control effectiveness.
• Patch. A skin patch worn on the body that releases the hormones estrogen and progestin into the bloodstream. It is most effective in people who weigh less than 198 pounds.
• Diaphragm or cervical cap. A dome-shaped rubber cup with a flexible rim that is inserted through the vagina to cover the cervix. This type of birth control must be inserted before having sex.
• Hormonal vaginal contraceptive ring. A ring that is placed inside the vagina around the cervix. The ring releases the hormones estrogen and progestin.
• Intrauterine device (IUD). Devices placed in the uterus through the cervix by a doctor. The IUD works by thickening cervical mucus to make it hard for sperm to enter the cervix. Or it prevents the fertilized egg from attaching to the wall of the uterus. IUDs containing hormones are also called intrauterine systems. They must be replaced every 3 to 8 years, depending on which device is chosen. Copper IUDs can last up to 10 years.

These surgeries result in the inability to become pregnant:

• Hysterectomy. Removal of the uterus and usually the ovaries and fallopian tubes. This is a permanent form of birth control.
• Tubal ligation or tubal occlusion ("tying the tubes"). Surgery to cut, cauterize, or band the fallopian tubes to prevent the egg from being transported to the uterus. Tubal ligation is designed to be a permanent method of birth control. Certain types of tubal ligations can be reversed. But the reversal procedure may not work.
• Salpingectomies. Surgery to remove both fallopian tubes. This is a permanent form of birth control.
• Vasectomy. Cutting or clamping the vas deferens. These are the tubes that carry the sperm from the testes. The testes still make sperm, but the sperm die and are absorbed by the body. This is a permanent male birth control measure.

The following are not reliable methods of birth control:

• Withdrawing before ejaculation
• Having sex during menstruation
• Standing up immediately after sex
• Douching after sex