What Is the Minipill?

Medically Reviewed by Poonam Sachdev on February 06, 2023
4 min read

The minipill is a type of birth control pill made with progestin, an artificial form of the hormone progesterone that your body makes. It's also known as the progestin-only pill (POP). 


Both are types of low-dose birth control pills. But minipills have only one type of hormone, progestin. Combination pills also contain a second female hormone called estrogen. Minipills may have fewer side effects, but they may be slightly less better at preventing pregnancy. 

Combination birth control pills prevent pregnancy by stopping ovulation. That's when your ovaries release an egg. They also slow down an egg's travel through your fallopian tubes, which helps stop sperm and your egg from joining. They do that by thickening the mucus inside your cervix and thinning the lining of your uterus. There are many combinations of these pills to choose from, depending on how often you want to have a period and the amount of hormones that are best for you. Packs of these pills include 21 active ones and seven inactive ones, or 24 active pills and four inactive ones.

Minipills also prevent sperm from reaching an egg, and a fertilized egg from implanting in the womb. Like combination pills, they thicken the mucus inside your cervix and thin the lining of your uterus. This helps keep a fertilized egg from implanting. But unlike combination pills, minipills only stop ovulation sometimes. There aren't as many choices of minipills as there are for combination pills. In each pack, all minipills contain the same amount of progestin, so you must take one every day.

When you talk about the dose of birth control pills, you're talking about the amount of hormones they contain. Most combination pills and all minipills are low-dose.

With combination pills, the more estrogen they have, the more side effects they may cause. Those can include breast tenderness, nausea, headaches, and, in rare cases, fatal blood clots. When birth control pills first became available in the 1960s, they had 150 micrograms of estrogen. Most combination pills today have 10-35 micrograms. Ultra low-dose combination birth control pills have 20 micrograms or less. Minipills have no estrogen.

You may want to go with the minipill if you:

Breastfeed. With estrogen in combination birth control pills, you may not make as much breast milk. Your doctor may recommend the minipill if you plan to nurse your baby.

Are over 35 and smoke, have high blood pressure, or have a history of blood clots. The minipill may be safer for you to take than combination birth control pills.

Want to avoid estrogen. The hormone may interact with other medicine you take. Estrogen also can give some women stomach pain or bad headaches.

Have dermatitis. The minipill may help treat this skin condition. Dermatitis causes red, swollen, sore skin. It may be linked with your menstrual cycle.

The minipill isn’t right for everyone. Your doctor may suggest you avoid it if you have:

  • Breast cancer or had it before
  • Liver disease
  • Had weight loss surgery
  • Any trouble taking the pill at the same time every day
  • Uterine bleeding and don’t know why
  • To take drugs for conditions like tuberculosis, HIV or AIDS, or seizures

The minipill comes in a pack of 28. Unlike combination birth control pills, there’s no row of inactive, or placebo, pills. It’s important to take the minipill every day and at the same time each day. Your body clears progestin more quickly than the hormones in combination birth control pills. If you take the minipill more than 3 hours outside of your usual time, it may not work as well to prevent pregnancy. If you miss the 3-hour window, use additional birth control like a condom or don't have sex for the next 2 days.

If you forget to take a pill, take one as soon as you remember. That may mean you take two pills in one day. Take them a few hours apart. Then take the next pill at your regular time.

When you first start the minipill, take it within 5 days of when your period starts. It takes time for the minipill to work. Use a condom every time you have sex in the first week after you start the minipill.

If you get pregnant while taking the minipill, it can cause problems. You’re more likely to have an ectopic pregnancy. This is when a fertilized egg implants outside of the uterus, such as in a fallopian tube. You won’t be able to continue with your pregnancy, and you may need surgery to remove the fetus.

Possible side effects of the minipill include:

  • Acne
  • Nausea
  • Fatigue
  • Headaches
  • Depression
  • Lower sex drive
  • Tender breasts
  • Cysts on the ovaries
  • Bleeding between periods
  • Skipped periods
  • Mood swings
  • Dizziness
  • Thinning hair

The minipill doesn’t protect you from sexually transmitted infections. Always use condoms to reduce your chance of disease.

Birth control isn't one-size-fits-all. It's a good idea to weigh the pros and cons of the minipill and other forms of birth control with your doctor.