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Birth Control Bingo: Minipills

Minipills (Progestin-Only Oral Contraceptives) are:

    • 99+% effective in one year of perfect use; less than one out of every 100 people will become pregnant
  • 90% effective in one year of typical use: 10 out of every 100 people will become pregnant

Additional Sources for Effectiveness Ratings and Use:

  • 91% typical use/99+% perfect use: Contraceptive Technology, 20th Revised Edition; Hatcher, Trussell, Stewart, Nelson, Cates, Guest, Kowal: Ardent Media, 2011.
  • 87% typical use/ 99.7% effective perfect use: Feminist Women's Health Center

Some adolescent-specific studies on birth control pills have shown that it is less effective for teens in typical use than it is for adults. One study found that teens' ability to use the pill properly was as low as only 45% with the first three months of use, and 33% with one year of use.

The What, the Why, the Where, the When, and the How-to: Like the combination pill, the minipill (sometimes called the progestin-only pill or POP) is an oral medication which is taken every day, around the same time each day, to prevent pregnancy. Unlike the combination pill, the mini-pill uses only one hormone, progestin, to achieve this. That hormone thickens cervical mucus to impair sperm mobility so they have a tough time getting into the uterus. They may also sometimes suppress ovulation. Because it does not act in three different ways like the combination pill does, minipills are slightly less effective. It is also far more important to take progestin-only minipills on time each day, so they have a lower typical use rate, which may be even lower for adolescents.

Also unlike combination pills, minipills do not have a placebo period: you need to take the same pill every single day of the month. Minipills can change monthly bleeding a good deal, but even on months when you don't have a monthly bleed, you'll go ahead unto your next pack without skipping any days. When you finish one pack of minipills, you just move right on to the next.


Think or know you used this method improperly, or know that you have had a pregnancy risk due to unprotected sex? It might not be too late for you to prevent an unwanted pregnancy with a method of emergency contraception.

Minipills are safe for people who cannot take combination pills or other methods with estrogens, such as those who smoke, are over 35, are breastfeeding, have increased cardiovascular risks or cardiovascular disorders or who suffer from migraine headaches. They can also be a good choice for those who want to use an oral contraceptive, but want a relatively quick return to their natural fertility cycles when they discontinue use. For those who have not done so well with other progestin-only methods, like Depo Provera, the minipill may be a good next choice as it contains less progestin than other methods. Be sure to discuss your health history and any current health issues with your healthcare provider so that they can be sure the minipill is safe for you.

Some typical effects of the minipill include shorter, lighter periods or even the absence of periods, mid-cycle spotting or unpredictable bleeding, less cramping, decreased PMS symptoms, weight gain, and/or more frequent yeast infections. The minipill may also increase the risk of ovarian cysts. Rare but more serious side effects can include allergic reactions, blood clots, embolism or stroke, heart attack, gallbladder disease, thrombosis or eye problems.

In most countries, you'll need to visit your sexual healthcare provider (who may also be your regular doctor) to obtain a prescription for the minipill to fill at your pharmacy. Some healthcare plans, national healthcare services and clinics will provide the pill for free. For those who have to purchase pills themselves, they tend to cost around the same as combination pills, between $30 and $50 each month.

With the Minipill it is very important to take one pill every day, within a three hour window every day. Unlike combination pills - which have a 12 hour grace period before a pill is late -- not taking minipills at very close to the same time each day can decrease effectiveness.

When you first start the minipill, it is advised to use a backup method for the first full cycle of pills, and some organizations advise using a backup for the first three months (mostly to account for users who take a while to get in the hang of taking pills on time daily).

For detailed instructions on how to use your particular pill, you can refer to the insert that comes with your pill, or see our listing of links for specific pill instructions here.


Some newer progestin-only pills have been demonstrated to work similarly to the combined oral contraceptive pill, one example being Cerazette. Their ability to work to primarily inhibit ovulation has put them at similar reliability and margin of error as the combined pill, and unlike traditional minipills, the "missed pill" window can range up to 12 hours. However, ALL minipills currently available in the US and Canada are the traditional type, which this page is based on. Please refer to the insert that came with your pills or call your pharmacist if you have any concerns, or aren't clear as to which type of pills you have.

Also be aware that certain medications and substances may interfere with the effectiveness of the minipill. If you are using or have, in your current pill cycle, used, any of the following it's best to use a backup method of birth control (like a condom) until your next new cycle:

  • Barbituates
  • Rifampin
  • Chloramphenicol
  • Nitrofuratonin
  • Griseofulvin
  • Benzodiazepines

If you are currently bulimic, and cannot control your urge to vomit at any given time that the pill will not be a good choice, as it may be less effective if a woman is currently vomiting for any other reason or has diarrhea.

What will/might you need to discuss or negotiate with a partner?

  • If you or they are or are not okay with ejaculation inside the vagina
  • Possible semen allergies or sensitivities (it is currently estimated as many as around 10% of people may have them), if not being combined with condom use
  • STI status and history, especially if not being combined with condom use

Some questions and answers about the pill:

Or, click on the tag for minipill for a larger list.

When Good Birth Control Does Bad Things: The minipill may fail if it is not taken on time each day: remember that with the minipill, taking it within the same three-hour time window every day is critical, as is taking a pill every single day, without fail.It may also fail if it is used without a backup method when a user starts the pill for the first time, or if taken in conjunction with other drugs or substances which may interfere with it. While nearly all BCP failures are simply due to not taking the pill every day without fail, there are -- though they are rare -- some people for whom, even when taken perfectly, the pill does not work for.

Other methods which can be used as a backup method with the minipill:

Other methods you might like if you like the minipill:

Why would the minipill be a good option for me? If any of the following are true:

  • You want a method which is highly effective when used properly
  • You want some of the possible benefits the minipill may offer, like shorter, lighter periods, decreased PMS symptoms or, in some cases, the absence of periods
  • You are looking for a method which you are completely in charge of yourself, where you don't have to rely on a partner to help with birth control
  • You are okay with unpredictable bleeding or spotting
  • You prefer an oral medication to shots, implants or vaginal or intrauterine devices, but cannot or do not want to use the combination pill
  • You don't want a method you have to think about at the time you're going to have sex

This is part of Scarleteen's Birth Control Bingo. Need to start over or anew? 


Don't forget: Statistically, sexually active young adults are as, if not more, likely to acquire a sexually transmitted infection (STI) as you are to become pregnant. Although 15-24-year-olds represent only one-quarter of the sexually active population, they account for nearly half of all new STIs each year, and of the 18.9 million new cases of STIs each year, 9.1 million (48%) occur among 15-24-year-olds (AGI). Often people have some funny ideas about who is most likely to get an STI, but the fact of the matter is that younger people -- of any sexual orientation, any economic class, any kind of relationship -- have been the highest risk group for some time now.

Condoms are the only method of birth control which also provide protection against STIs. It's pretty typical for younger people to ditch condoms if they have another method of birth control, so just remember that STIs are still a risk if you're using another method. You can read all about safer sex here -- Safe, Sound & Sexy: A Safer Sex How-To -- but the rule of thumb most medical experts and prevention organizations suggest, which we also encourage at Scarleteen is six months of safer sex, six months of sexual monogamy, and then TWO full STI screenings for each partner -- once at the start of that six months, once at the end -- before ditching latex barriers.

Information on this site is provided for educational purposes. It is not meant to and cannot substitute for advice or care provided by an in-person medical professional. The information contained herein is not meant to be used to diagnose or treat a health problem or disease, or for prescribing any medication. You should always consult your own healthcare provider if you have a health problem or medical condition.