Portrait of Nathaniel Scharping
Nathaniel Scharping
Portrait of Lauren A Koenig
Lauren A Koenig, PhD

Hormonal stops ovulation, meaning your won’t release an egg. It’s the main way all kinds of prevent pregnancy, and it’s one of the reasons these kinds of are so effective.

But because ovulation isn’t really something you can feel, it’s pretty natural to wonder if is doing its job. The bleeding that can accompany can make it seem like you’re getting your monthly period, too, which can add to the confusion (spoiler: it’s called withdrawal bleeding, and is not technically your period).

Thankfully, decades of studies show that is safe and highly effective at preventing pregnancy, meaning it works more than 99 percent of the time when used correctly.1 Options like the birth control pill, patch, , ring, and more all keep you from getting pregnant by delivering sex hormones that stop your from releasing an egg.2 Non-hormonal like condoms and the copper IUD also prevent pregnancy, but they don’t stop ovulation.2-3

So what’s going on inside your body when you’re on hormonal ? And what if you do happen to ovulate while taking ? Read on for the answers!

How does stop ovulation?

Ovulation is when your release an egg, and it typically happens about 14 days into your menstrual cycle, though the exact day can vary a bit. It’s a carefully orchestrated process that’s cued by a few different hormones.4

Hormones over the course of cycle

First, gonadotropin-releasing (GnRH) causes the pituitary gland to release () and (). tells a follicle, a small sac that contains an egg, to begin to mature, and around day 14 of your cycle, a spike in causes the follicle to release an egg. The egg travels down your fallopian tubes for about 24 hours, a journey during which it can meet a sperm and become fertilized.4

Learn more about hormones and their functions.

But none of that happens if you’re taking . All forms of contain sex hormones that interrupt the normal signals telling your body to ovulate, meaning no egg gets released. It’s similar to the process that naturally occurs in your body to prevent ovulation during a pregnancy. (That’s why people often say “tricks your body into thinking it’s pregnant.”)5

All contains , an artificial version of the sex . Different kinds of deliver different varieties and amounts of , but they’re all highly effective at preventing pregnancy. Some kinds contain as well.6-8

Progestin does most of the work in preventing ovulation. It inhibits the release of GnRH, which reduces the amount of and present in your body. Without the presence of and the corresponding spike in , follicles don’t develop, and they don’t get a signal to release an egg. can help out by slowing the release of and also inhibiting follicular development, though it’s not necessary to have it. All in all, if no egg gets released, there’s no ovulation, which means no egg to fertilize, and no possibility of pregnancy.5


Like what you’re reading? Get the latest straight to your inbox 💌

This field is for validation purposes and should be left unchanged.


Are there signs of ovulation while on ?

With or without , there aren’t any obvious signs when ovulation occurs. But there are ways to track whether it’s happening. When you ovulate, your body temperature and cervical mucus change in predictable ways9 — people using the fertility awareness method (FAM) of often use these signs to track when they’re ovulating. (Side note: FAM is not considered , and it’s quite difficult to do perfectly.)

Can you ovulate on ?

Hormonal is highly effective at preventing pregnancy when used correctly. If used incorrectly, which can mean missing a pill or taking it late, or forgetting to replace a patch or ring at the right time, is less effective — effectiveness with “typical use” varies, but is usually between 90 and 95 percent.2

There aren’t good numbers on how likely it is to still ovulate while using . They’re more than 99 percent effective with perfect use, so the probability is sure to be very small. If you miss a pill, there is a chance that ovulation could happen, though the probability depends on what pill you’re taking and what week of the pack you’re in.

For combined pills, if you miss just one day, you can catch up by taking the missed pill as soon as possible. If you miss two days of a combined pill, you may not be protected against pregnancy, and may need to use emergency contraception or another method like a condom.10 Progestin-only pills are less forgiving: If you take one more than three hours after you normally would, you might not be protected against pregnancy. You should take the pill as soon as you can, and use a condom or other supplemental method for 48 hours after that.10

Need help choosing a birth control method? Shop The Birth Control Test.

Can you get pregnant on ?

Even if you do ovulate while on , the odds of pregnancy are still low. That’s because the sex hormones in have secondary effects that also make a pregnancy less likely. thickens cervical mucus, which stops sperm from getting through, and it also thins the lining of your , or , to prevent an egg from implanting there.5

In other words, preventing ovulation isn’t the only way can prevent a pregnancy. All together, these are what make 99 percent effective when used correctly.

Learn more about your options

Finding an effective that works for you takes knowledge of both the options out there and your own body. The best place to start is with The Birth Control Test, which uses your unique biology to show you which options might be a good fit for you.

  1. How effective is contraception at preventing pregnancy?NHS.uk (2020 Apr 17).
  2. ContraceptionCDC.gov (2023 May 01).
  3. Ortiz, Maria Elena, Horacio B. Croxatto, and C. Wayne Bardin. “Mechanisms of action of intrauterine devices.” Obstetrical & Gynecological Survey 51.12 (1996): 42S-51S.
  4. Holesh, Julie E., Autumn N. Bass, and Megan Lord. “Physiology, ovulation.” StatPearls [Internet] (2017).
  5. Cooper, Danielle B., Preeti Patel, and Heba Mahdy. “Oral contraceptive pills.” StatPearls [Internet] (2017).
  6. U.S. Food & Drug Administration (FDA). “Highlights of Prescribing Information: Mirena.” AccessData.FDA.gov. (2022 Aug).
  7. U.S. Food & Drug Administration (FDA). “Highlights of Prescribing Information: Yasmin.” AccessData.FDA.gov (2022 Apr).
  8. U.S. Food & Drug Administration (FDA). “Highlights of Prescribing Information: NuvaRing.” AccessData.FDA.gov (2013 Oct).
  9. Centers for Disease Control and Prevention (CDC). “Classifications for Fertility Awareness–Based Methods.” CDC.gov (2023 Mar 27).
  10. What should I do if I miss a pill (combined pill)?NHS.uk (2019 Feb 14).