Birth Control Side Effects and Risks

Medically Reviewed by Brunilda Nazario, MD on May 17, 2024
5 min read

When you’re choosing a birth control method, it’s important to consider the benefits and different side effects and risks you might have. Before you decide, compare your options to figure out which is the best for you.

If you have questions about how each form of birth control may affect your body, talk to your doctor. You can also do some research to get a better understanding of the different types.

Combined hormonal birth control contains man-made forms of estrogen and progestin. Options include:

  • Birth control pills 
  • The vaginal ring (Annovera, EluRyng, or NuvaRing) 
  • The patch (Twirla, Xulane, or Zafemy)

These methods all prevent pregnancy if taken properly. This means you’ll need to:

  • Take the pill at the same time every day. 
  • Put on a new patch each week. 
  • Replace the vaginal ring once a month. 

These forms are about 99% effective if you use them exactly as prescribed, also called perfect use. With typical use, your chances of getting pregnant go up slightly. Out of 100 people who use combined hormonal contraception, around 6 to 9 may get pregnant each year. 

There are pros and cons to combined hormonal birth control. The pill could cause minor symptoms, especially in the first few months of starting it, such as:

Birth control methods with the hormone estrogen could also make your risk of blood clots go up. For this reason, doctors don’t suggest these methods if you’re over the age of 35 and smoke. But if you’re in good health and don’t smoke, these types of birth control can be used up until you reach menopause.

The upsides to these forms of contraception include:

  • Lighter periods
  • Less cramping
  • Less acne (for the pill)
  • Fewer menstrual headaches (for the pill)
  • Lower risk of uterine and ovarian cancer (for the pill)

These pills only contain one hormone (progestin), instead of two hormones like the combined hormonal pill. You’ll need a prescription for most progestin-only pills, except for one kind, an over-the-counter option sold under the brand name Opill. 

They work by thickening your cervical mucus so sperm can’t get to your eggs. The progestin hormone in the pill will also thin the lining of your uterus and allow you to have lighter periods. You need to take this pill every day.

About 13 people out of 100 will get pregnant each year on the minipill. There’s also a slightly higher risk you could have an ectopic pregnancy. This happens when the fertilized egg implants itself outside of your uterus.

Possible side effects of this method include:

The arm implant is a hormonal (progestin) device about the size of a matchstick. Your doctor puts it directly under the skin in your arm. It can work for up to 3 years.

This method is almost 100% effective and is the most reliable form of reversible contraception along with IUDs. 

Nexplanon’s side effects can be like other progestin-only birth controls. The most common one is irregular bleeding. In most cases, your periods will become very light and may even stop after 6-12 months of having the implant. This is safe.

An IUD is a tiny device that your doctor will put into your uterus. There are two types of IUDs. One is copper and the other is plastic. The plastic IUD has a very low amount of progestin.

You can keep the copper IUD in for up to 10 years while the plastic version can be effective for anywhere from 3-5 years depending on which type you choose. Both IUDs have close to a 100% success rate.

The copper IUD might cause more painful and heavy periods for some people. But it doesn’t use hormones, which is a benefit for some people, such as breast cancer survivors. Other side effects could include:

  • Irregular bleeding between periods
  • Cramps

Hormonal IUDs have similar side effects to other progestin-only birth control methods. You might have irregular or light bleeding, and then eventually no bleeding at all, which is normal. You might also notice:

  • Acne
  • Headaches
  • Tender breasts
  • Mood changes
  • Cramps or pelvic pain

Depo-Provera is a form of progestin. You’ll get this form of birth control as an injection in your bottom or arm. Each dose will protect you against pregnancy for 12-15 weeks.

This method is about 99% effective if you use it properly. But with typical use, six out of 100 people will get pregnant yearly. This can happen if you don’t get all four yearly required injections on time.

The bleeding side effects of Depo-Provera are like those of other progestin-only birth control methods. About half of the people on this method for more than a year will stop getting their periods. You may also notice irregular bleeding, especially during the first year.

Rarely, you might gain weight on Depo-Provera. This is the only type of birth control that causes this.

Barrier methods are nonhormonal forms of birth control. These can go on or inside of you or your partner to protect from pregnancy. They include:

Male condoms. These are thin rubbery coverings that go on an erect penis. When you use them properly, male condoms are 98% effective. However, 18% of people will still get pregnant every year with condoms due to improper use. They also help protect you and your partner from sexually transmitted infections (STIs).

Female condoms. This type of condom goes inside your vagina and covers your cervix with the other side covering your labia. Around 21% of people will get pregnant each year using this method. Follow the directions carefully to lower your chance of unplanned pregnancy.

Diaphragm. This type of birth control goes inside your vagina and against your cervix. It’s important to also use spermicide with this method. About 12% of people will get pregnant each year with this method, but it’s more effective if you follow the directions carefully.

Cervical cap. The cervical cap fits over your cervix to protect you from pregnancy. About 21% of people get pregnant per year while using it. You can lower your chance of getting pregnant by following the instructions exactly.

Sponge. This device goes inside of your vagina and acts as a barrier for sperm. It also releases spermicide to kill sperm cells. About 32% of people will become pregnant each year using this type of contraception. Use it as instructed to lower your risk of pregnancy.