Most birth control pills have estrogen and progestin hormones. Some only have progestin. In both cases, the pill has to be taken every day, at about the same time, to prevent ovulation (the release of an egg from an ovary). Since no egg is released without ovulation, the sperm has nothing to fertilize and pregnancy can’t happen.

Combination (The Pill)

The pill contains estrogen and progestin that work to prevent pregnancy by stopping ovulation and thickening cervical mucus. While all combination pills work in this way to prevent pregnancy, they can sometimes have different side effects.

How effective is it against pregnancy?

• Typical use: Prevents pregnancy 93% of the time
• Perfect use: Prevents pregnancy 99% of the time
• Using the pill correctly and consistently increases its effectiveness. If you use the pill perfectly, it is about 99% effective at preventing pregnancy.

How to use:

• Must take the pill daily, at the same time every day

Pros:

• Can use while breastfeeding
• You can become pregnant right after stopping the pills

Cons:

• Often causes spotting between periods, which can last for months but can improve over time
• Does not protect against HIV or other STIs – use a condom with this method

Progestin-Only Pills (POPs)

Just as the name says, this pill only contains progestin. It prevents pregnancy by thickening the cervical mucus and preventing ovulation so that the sperm cannot fertilize an egg. It can also thin the lining of the uterus so that it is more difficult for the egg to attach to the wall of the uterus. The progestin may also change periods. Some people have irregular bleeding, and others have no period.

***Beginning in 2024, Opill, the very first birth control pill in the U.S. that can be purchased over-the-counter without a doctor’s prescription, became available. It can be purchased online (for as little as $15 per month) or in any store along with your Tylenol, vitamins, condoms, or anything else you would buy at a drugstore*** (VIDEO)

How effective is it against pregnancy?

• Typical use: Prevents pregnancy 93% of the time
• Perfect use: Prevents pregnancy 99% of the time
• Using the pill correctly and consistently increases its effectiveness. If you use the pill perfectly, it is about 99% effective at preventing pregnancy.

How to use:

• Must take the pill daily, at the same time each day

Pros:

• Can use while breastfeeding
• You can become pregnant right after you stop taking the pills

Cons:

• Often causes spotting, which can last for many months
• May cause irregular periods
• Does not protect against HIV or other STIs – use a condom with this method