Birth Control Pill Overview










Birth control pills are oral contraceptives that, when taken correctly, are extremely effective at preventing pregnancy. The hormones in the pills prevent ovulation, thicken the cervical mucus, and change the endometrial lining of the uterus so that sperm cannot meet or fertilize an egg.³There are two main types of birth control pills: combination pills and progestin-only pills. Combination pills contain the hormones progestin and estrogen. Progestin-only pills contain progestin but do not contain estrogen.¹

What Do Birth Control Pills Look Like?

Birth control pills come in packages that typically contain one month’s supply of pills. Combination pills come in either 28- or 21-day packs. In a 28-day pack, there are 21 “active” pills (containing estrogen and progestin) taken every day for three weeks, and the last four to seven pills are taken as “reminder” or placebo pills that contain no hormones. A 21-day pack is similar to a 28-day pack, except there are no placebo pills taken during the last week. Bleeding occurs during that last week when no hormones are taken. Combination pills can also come in 84-day packs that allow for menstrual bleeding only four times a year. These types of combination pill packs are called “extended” or “continuous use” pills.¹ Progestin-only pills come in 28-day packs. Each pill in the 28-day progestin-only pack is an “active” pill, which means they each contain a small amount of progestin. There are no placebo breaks taken between active pills because progestin-only pills do not control a female’s menstrual period


How to Use Birth Control Pills

Birth control pills are most effective when taken around the same time every day. Progestin-only pills must be taken at precisely the same time each day because they contain only a small amount of progestin that can exit the body in as little as 24 hours, leaving a woman at risk for pregnancy.³ Combination pills allow for a little more temporal fluctuation because the hormones in them are strong enough to prevent pregnancy for a time when the pill is not taken (for example, during the week of inactive pills). It is, however, a good idea to take them as regularly as possible to maximize their effectiveness.¹



Choosing the Right Pill

Combination pills tend to be more effective at protecting against pregnancy than progestin-only pills. Combination pills also regulate the menstrual cycle, while progestin-only pills can sometimes make periods more irregular.

Combination pills contain estrogen, which causes side effects that are not typically associated with progestin-only pills. The following side effects are associated with combination pills:

  • Increased risk for blood clots and heart problems

  • Bleeding or spotting between periods

  • Breast tenderness

  • Weight gain

  • Nausea and vomiting

  • Mood changes

  • Headaches

  • Decreased libido


Some of these side effects may occur with progestin-only pills but are more common and more severe with combination pills. In addition, it may take longer for pregnancy to occur or for menstrual cycles to return to normal after you stop taking the combination pill than it would after stopping the progestin only pill.²

Combination birth control pills can increase the risk of developing or worsening certain serious medical conditions. The risks depend in part on a woman’s medical history. Deep vein thrombosis, heart attack, and stroke are some of the major risks associated with combination birth control pills. The combination pill is NOT recommended for women who experience the following:

  • Are over the age 35

  • Smoke cigarettes

  • Have unexplained vaginal bleeding

  • Have breast cancer

  • Have had a heart attack, stroke , or other serious heart problems

  • Have liver disease or liver cancer

  • Have high blood pressure or cholesterol levels

  • Have a history of blood clots

  • Have frequent migraine headaches

  • Have diabetes

  • Are or will be on bedrest for a prolonged period of time


Click here to find out more about whether combination pills are be right for you.


For women who find that the combination pill is not suitable for their needs, there is the progestin-only pill. The progestin-only pill is recommended for women who experience the following:

  • Are breastfeeding; the estrogen in the combination pill inhibits milk production⁴

  • Smoke cigarettes, are older than 35, or have health problems like heart disease, blood clots, high blood pressure, and migraines. The lack of estrogen in progestin-only pills makes them less likely to cause blood clots.³


Click here to find out more about progestin-only pills.


You should not take either type of pill if you are pregnant or suspect that you are pregnant. Talk to your doctor if you are experiencing symptoms of pregnancy.


Birth control pills do NOT protect against sexually transmitted infections (STIs). To reduce the risk of contracting or spreading STIs, condoms or other forms of barrier methods should be used.



Birth control pills can be purchased at a pharmacy with a prescription from a doctor for about $15-50 dollars a month, depending on the type of pill and whether or not it is covered by insurance. This price typically does not include the cost of the doctor’s examination required to get a prescription for birth control pills. Health clinics, such as Planned Parenthood, may provide their services at lower prices (or even free of charge). For example, the price of one pack of pills can be discounted if you sign up for 6 months worth of pills. Some clinics are even willing to adjust the price of birth control pills according to one’s annual income and insurance coverage (or lack thereof). Most U.S. states allow health clinics to make birth control available to minors for free and without parental consent. As of 2010, the Affordable Care Act allows private health insurance companies to provide birth control without a copay. Contact your insurance provider for more information about whether or not your birth control pills are covered by your plan.¹



What if I Want to Get Pregnant?

Because birth control pills have no effect on fertility, you can become pregnant immediately after you stop taking the pill (though your cycles may not be regular for a few months). With combination pills, fertility typically returns to normal within two weeks of stopping the pill, and progestin-only pills allow you to get pregnant in even less time.² Despite the fact that it is safe to become pregnant right away, it may be wise to wait until your cycles are regular (this may take up to 6 months) because your physician will more easily be able to estimate the due date of the baby.²images.png



Birth control pills are oral contraceptives that prevent pregnancy when used correctly. There are two main types of birth control pills (combination and progestin-only) that have differing side effects and usages. These two main types of birth control pills also have specific advantages and disadvantages that should be considered when deciding which type of birth control pill is more ideal.


For more information regarding various types of contraception, consult our Birth Control Comparison Chart and check out the video below!



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Last Updated: 7 November 2016.


1.  Parenthood, Planned. "Birth Control Pills - Birth Control Pill - The Pill." Birth Control Pills - Birth Control Pill - The Pill. Planned Parenthood, 01 Nov. 2016. Web. 15 Nov. 2016.

2.  Mayo Clinic Staff. "Combination Birth Control Pills." Mayo Clinic. Mayo Clinic, 13 Aug. 2015. Web. 15 Nov. 2016.

3.  Mayo Clinic Staff. "Minipill." Mayo Clinic. Mayo Clinic, 26 Nov. 2014. Web. 15 Nov. 2016.