A Guide to Birth Control Pills: Uses, Side Effects, Effectiveness, Cost, and More

The basics

Birth control pills (also called “the pill”) are the most commonly used form contraception in the U.S. after surgical sterilization. The most recent estimate is that 14% of women in the U.S. ages 15 to 49 (over 10 million women) take the pill, which is not surprising since it’s been around for over 50 years.

Birth control pills contain human-made versions of the sex hormones estrogen and progesterone. These help prevent pregnancy in a few different ways. But the pill is not only used for contraception. It’s also very effective at treating heavy and painful periods.

But be aware that the pill does not protect against sexually transmitted infections (STIs). Here’s a guide to commonly asked questions about birth control pills, including efficacy, possible side effects, and how to save on them.

Take our quiz: Types of birth control

What are birth control pills used for?

Birth control pills have been used for decades to prevent unplanned pregnancies. Generally speaking, they’re low cost, easy to use, and tolerated well.

But the pill is not the only form of contraception — there are many other options. Examples include intrauterine devices (IUDs), medication patches, and even surgery (which is permanent). 

The pill can do more than prevent unplanned pregnancy. It is also used to treat many symptoms and conditions related to sex hormones. While this guide will focus on the pill as it’s used for contraception, it’s worth mentioning the other conditions it can treat, such as:

• Premenstrual syndrome (PMS)

• Premenstrual dysphoric disorder (PMDD)

• Endometriosis 

• Heavy menstrual bleeding disorders

• Polycystic ovary syndrome (PCOS)

• Acne or unwanted hair growth due to hormones

How does the pill work?

When taken each day as directed, the pill prevents pregnancy in the following ways: 

• Stops the ovaries from releasing eggs (ovulation): This is the main way birth control pills prevent pregnancy.

• Thickens the cervical mucus: This makes it harder for sperm to reach an egg.

• Thins the lining of the uterus: This makes it harder for a fertilized egg to implant and start a pregnancy.

Using the pill for contraception is reversible. In other words, you can get pregnant when you stop taking it. In order for the pill to work best, you need to take it every day — no exceptions. So it’s helpful to make it part of your routine, like taking it every morning when you brush your teeth, or every night before going to sleep. Medication reminder apps can also be helpful.

Read more like this

Explore these related articles, suggested for readers like you.

Will Birth Control Pills Make Me Gain Weight? Probably Not

Is It Safe to Delay My Period?

Don’t Want to Take the Pill? A Guide to 7 Birth Control Alternatives

Kelnor: Uses, Side Effects, Dosage, & More

View more

Combination pills

Most birth control pills contain some combination of the female sex hormones estrogen and progestin (an absorbable form of progesterone). These are known as combination pills. Usually, with combination pills, you take a pill each day for 21 to 24 days, followed by a pill without hormones (a placebo) or no pill for 4 to 7 days. During this hormone-free time, you can expect to have withdrawal bleeding, like a period.

The most common combination pills have the same amount of hormone in each pill. These are called monophasic pills. Some pills have different levels of hormones from one week to the next, like your normal monthly cycle would. These are called phasic (biphasic or triphasic) pills.

Unless your healthcare provider tells you otherwise, it’s OK to skip the 4- or 7-day break. In fact, some forms of the pill are designed to delay your period for a few months or even a year. These are called extended-cycle or continuous-use pills.

When starting combination pills for the first time, you may need backup contraception (such as a condom) if you are sexually active. It all depends on the timing of when you start taking the pill:

• If you start the pill within 5 days of when your period started, you don’t need backup contraception.

• If you start the pill more than 5 days after your period started, you’ll need backup contraception for 7 days.

• If you’re not sure when your last period was, use contraception for 7 days to be safe.

‘Mini pills’

Progestin-only pills — sometimes called “mini pills” — are a good option for people who can’t take combination pills. And the FDA-approved Opill (norgestrel) may be a good fit for people who want an OTC pill option (it’s scheduled to be available in early 2024).

These pills work the same way as combination pills, except progestin-only pills aren’t as good at stopping ovulation. The body also processes them faster, so you have to take them at the same time every day.

Progestin-only pills come in a 28-day pack. In some packs, each pill contains a progestin. In others, there are 24 progestin pills and 4 placebos.

When starting progestin-only pills for the first time, you may need backup contraception if you are sexually active. Again, it depends on your timing:

• If you start the pill within 5 days of when your period started, you don’t need backup contraception.

• If you start the pill more than 5 days after your period started, you’ll need backup contraception for 2 days.

When in doubt, use backup contraception for 2 days to be safe.

How effective is the pill?

If you’re considering taking the pill to prevent pregnancy, you’ll want to know how well it works. How effective the contraceptive pill is at preventing an unplanned pregnancy depends almost completely on how well you remember to take the pill each day. 

With “perfect use,” when you take the pill every day (and at the same time with a mini pill) without forgetting any, less than 1 person in 100 has an unplanned pregnancy every year. In other words, it’s over 99% effective.

With “typical use,” forgetting to take the pill occasionally or taking a mini pill late, birth control pills are about 91% effective. So, 9 out of 100 people who use the pill have an unplanned pregnancy every year.

The mini-pill must be taken at the same time every day (within a 3-hour window) to work. If this 3-hour window passes, you may not be protected against pregnancy.

Combination pills are a little more forgiving. As long as you take your pill before the day is over, you’re still protected against pregnancy. But taking it at the same time every day can make it easier for you to remember to take it.

Some medications can make the pill less effective, no matter how regularly you take it. Be sure to share your list of medications with your healthcare provider and pharmacist when asking about birth control options.

What are possible side effects of birth control pills?

After starting the pill for the first time, or when switching to a new one, some people experience side effects. This is normal, as your body gets used to the hormones. 

Some common side effects include: 

• Headaches 

• Nausea 

• Breast tenderness

• Changes to your period

• Breakthrough bleeding or spotting

These side effects are usually temporary and tend to get better after the first few months. If you continue to struggle with side effects, reach out to your healthcare provider, as you may need to switch to a different kind of pill.

Can the pill cause weight gain?

Many people think that the pill causes weight gain. But, in a large review of studies, no link was found between the pill and significant weight gain. And another large review didn’t find a difference between combination and progestin-only birth control in terms of weight gain.

Mood changes

Mood changes are another possible issue with the pill. Each person reacts differently to hormones, and there are so many things that can influence your mood. But it’s difficult to conduct clinical studies on this.

That said, a large study of over 1 million women found a link between all types of hormonal contraception and later use of an antidepressant. This link was found to be stronger in younger women and adolescents. Several other studies have found similar links between birth control pills and mood disorders. However, experts have noted that newer birth control pills may be less likely to cause mood changes than older pills.

If you think your contraception is affecting your mood, be sure to speak with your healthcare provider.

Combo birth control pills and blood clots

In addition to the side effects mentioned above, there is a more serious issue related to combination pills. There is a known link between hormonal contraception and the risk of blood clots, heart attack, and stroke. The risk is highest in the first year of use. This risk is not specific to the pill, however. A higher risk of blood clots is also seen with other forms of contraception that use hormones, such as vaginal ring birth control.

Are the side effects of progestin-only pills different?

Not really. The side effects listed above can also be seen with progestin-only pills. But irregular and unpredictable bleeding tends to be the most common side effect of progestin-only birth control. While it’s commonly believed that the mini-pill may cause acne, a link has not been established. Both combination and progestin-only pills can cause acne as a side effect.

Progestin-only pills are thought to be safer for women at high risk of blood clots. However, the type of progestin is important. Research suggests that pills containing drospirenone and desogestrel, a type of progestin, might be linked to an increased risk of blood clots. We understand this information can be confusing, so be sure to speak with your healthcare provider about any concerns.

Who should not take birth control pills?

The pill might be the most commonly used reversible birth control, but that doesn’t mean it’s right for everyone. Here’s what you need to know about who should avoid the pill.

Who should avoid combination pills

You should not take combination birth control pills if you are 35 years of age or older and smoke. You should also not take them if you have certain medical conditions, such as:

• Blood clotting disorder

• Blood clot or stroke in the past 

• Breast cancer

• Diabetes with kidney, eye, nerve, or blood vessel problems

• Heart disease

• Liver disease

• Lupus

• Migraine with aura

• Uncontrolled high blood pressure

• Vascular disease

Who should avoid progestin-only pills

You should not take progestin-only pills if you have:

• Breast cancer

• Lupus 

• Liver disease 

Breastfeeding mothers

Be sure to speak with your healthcare provider before starting the pill if you just had a baby and/or you are breastfeeding. They might suggest that you wait to start the pill, or recommend a different type of contraception. Progestin-only pills and some other forms of contraception can be used while breastfeeding. Combination birth control pills aren’t usually recommended because they can affect your milk supply.

Choosing the best pill for you

There are so many birth control pill options out there, it can be overwhelming. And based on the discussion about side effects and risks above, you’ve probably assumed that the best choice for you will depend on your medical history. You’d be right.

But there are other things to think about, such as what you want out of your birth control, how you’ve reacted to hormones in the past (if at all), and whether or not you have health coverage. You might also have questions like these:

• Which pill is best for mood symptoms? 

• Which pill is best for PMDD or severe PMS?

• Which pill is best for acne?

• Which pill is best for women with endometriosis?

• Which pill is best for women with larger bodies?

These are all great questions, and we suggest discussing these things with your healthcare provider. There’s not really a “best” pill for anything, but some may be better than others in certain situations:

• Monophasic or continuous cycle pills may be better for mood symptoms related to PMDD. But only Yaz (drospirenone / ethinyl estradiol) is FDA approved to treat the condition.

• Combination pills, such as Tri-Sprintec (ethinyl estradiol / norgestimate), Beyaz (drospirenone / ethinyl estradiol / levomefolate), and Tilia Fe (ethinyl estradiol / norethindrone acetate / ferrous fumarate) are best if you have hormonal acne. 

• Combination pills are more risky in people with a body mass index (BMI) over 30 kg/m²because of the higher risk of blood clots. That said, if you are young with no history of blood clots and you don’t smoke, then the risk increase is pretty small.  

Whatever your personal circumstances, you’ll probably have more than one thing to consider when finding the right contraceptive. It can be frustrating, but if you’re just starting out, it’s hard to predict how your body will react to the hormones. Even once you are settled on the pill, you’ll probably go through a certain amount of trial and error before finding the pill that is best for you.That said, here’s a helpful guide to birth control options that might help you choose.

Getting birth control pills

There are a few options for getting birth control pills, depending on where you live.

With a prescription

In many places in the U.S., you need a prescription for birth control pills. That means contacting your healthcare provider and probably going in for a visit. If you don’t have insurance, or time to wait for an appointment, there are several telehealth services that can provide a consultation and prescription online.

Without a prescription

In some states, you don’t need a healthcare provider’s prescription for birth control. If you live in these states, you can get the pill from your pharmacist:

• Arizona

• Arkansas

• California

• Colorado

• Delaware

• Hawaii

• Idaho

• Illinois

• Maryland

• Minnesota

• Nevada

• New Hampshire

• New Jersey

• New Mexico

• North Carolina

• Oregon

• South Carolina

• Utah

• Vermont

• Virginia

• Washington, D.C.

• West Virginia

You will still need to answer questions about other medications you’re taking and any medical issues you have. But it could save you some time. Use this tool to find a pharmacy that can prescribe birth control near you.

And starting in early 2024, you will be able to get Opill, a progestin-only pill, without a prescription. Check back with GoodRx for ways to save on this OTC birth control option.

How to save on birth control pills

If you have health insurance, birth control pills are likely to be fully covered under the Affordable Care Act. If you’re uninsured or underinsured, there are still many ways to save on birth control pills.

GoodRx can help you navigate your options, which may include GoodRx discounts, copay savings cards, and patient assistance programs. You can find birth control prices as low as $7 with a free GoodRx discount.

Savings opportunities are also available for select brand-name products, such as Nextstellis and Lo Loestrin Fe.

For example, anyone with a valid prescription, regardless of insurance status, can use GoodRx to purchase a 28-day supply of Nextstellis at an exclusive cash price of $65. And if you have commercial insurance, you may be eligible to pay as little as $0 for Nextstellis using a savings card from the manufacturer. GoodRx can also help you access a 28-day supply of Lo Loestrin Fe at an exclusive cash price of $99. For those with commercial insurance, you may be eligible to pay as little as $25 for Lo Loestrin Fe using a manufacturer savings card.

Keep in mind

Remember that birth control pills do not protect against STIs, such as:

• Herpes

• Gonorrhea

• Chlamydia

• HIV

You should use a male or female condom if you’re worried about getting infected, but remember they are not 100% effective.

Additionally, women who take the pill may be at a slightly higher risk for breast cancer than women who don’t use hormonal contraception. Studies suggest all forms of hormonal contraception carry this risk. But your risk returns to normal about 10 years after coming off birth control. Birth control pills also slightly raise the risk of cervical cancer. As with breast cancer, this risk goes back to normal after stopping the pill.

The pill can decrease the risk of several other cancers, including:

• Colorectal

• Endometrial

• Ovarian

• Lymphatic

• Blood cancer

More research is needed to understand these risks.

When you choose the best contraception for you, we suggest weighing all the pros and cons of contraception — not just these risks — to choose what is best for you.

Why trust our experts?

Written by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined clinical medicine with her passion for education and content development for many years. She served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

Reviewed by:

Stacia Woodcock, PharmD

Stacia Woodcock, PharmD, is a pharmacy editor for GoodRx. She earned her Doctor of Pharmacy degree from the University of Kentucky and is licensed in New York and Massachusetts.

Reviewed by:

Patricia Pinto-Garcia, MD, MPH

Patricia Pinto-Garcia, MD, MPH, is a medical editor at GoodRx. She is a licensed, board-certified pediatrician with more than a decade of experience in academic medicine.

Our editorial standards

Meet our experts