How does birth control work? Well before we answer this important question, we need to understand the various contraception methods that are available and their effectiveness.

Abstinence
Natural Family Planning/Rhythm Method
Barrier Methods
Contraceptive Sponge
Diaphragm, Cervical Cap and Cervical Shield
Female Condom
Male Condom
Hormonal Methods
Combined pill
Progestin-only pill
The Patch
Shot/Injection
Vaginal Ring
Implantable Devices
Implantable Rods
Intrauterine Devices
Permanent Birth Control Methods
Sterilization Implant
Surgical Sterilization
Emergency Contraception

Now that we have listed the different contraception measures available, let us look at each to understand, how birth control work.

Abstinence works as the couple stay from sex, for a specified period, thus preventing pregnancy. Natural Family Planning/Rhythm Method works effectively if the menstrual cycle is calculated correctly.

The most fertile days when women can get pregnant are 5 days before and 3 days after ovulation. A barrier method can be used in those days in order to prevent any unplanned pregnancy.

In the barrier method the sperm is prevented from traveling to the egg, thus preventing fertilization.

The contraceptive sponge is a disk shaped device, which is placed in the inside of the vagina, it contains spermicidal and effectively kills the sperm. You will need to leave it inside for at least six hours to prevent pregnancy.

The diaphragm, cervical cap and cervical shield are other barrier methods that prevent the sperm from entering the cervix. You will need the help of a doctor to place the diaphragm and cervical cap inside the vagina.

These barrier methods need to be left inside for at least six hours to be effective.
Male and female condoms also work by preventing the sperm from going inside.

Both the couples must not wear respective condoms at the same time. You can use the condom just once while having sex.

Pills are the most popular and effective contraception methods used. They work by preventing ovulation and thickening the lining of the uterus wall, preventing the sperm’s advance.

Pills need to be taken daily, in order to be effective.
The patch is worn on the lower part of the body. It releases hormones in the body, preventing pregnancy.

You would need a new patch every three weeks. Injections stop the ovaries from releasing the egg and need to be taken every three months.
Vaginal worn as the name suggests is worn in the vagina and releases progestin and estrogen hormones that prevents pregnancy.

You can wear the ring for a period of three weeks. Implantable rods and IUD can be inserted by the doctor and are effective as long as five years. They work by releasing hormones thus preventing ovulation.

Sterilization is the more permanent method of contraception used, where a surgical procedure is done to prevent pregnancy. Emergency contraception is taken when unprotected sex increases the risk of unplanned or unwanted pregnancy.

As you aware of how does birth control work, you will able to take a better decision on which contraception measure to use.