How hormonal birth control affects your ovulation

how birth control affects ovulation

Have you ever been unsure about what hormonal birth control does to your ovulation?

You’re not alone. 

Laying the groundwork: ovulation

First and foremost, let’s get a running definition of ovulation. The term “ovulation” is thrown around a lot, but most people don’t actually know what it means or what it does to your body. Growing up, I didn’t even understand that there was a difference between ovulation and menstruation (whoops). 

Ovulation happens when an egg is released from your ovaries. It typically occurs in the middle of your menstrual cycle and indicates the highest fertility within that cycle. In other words, it's when you're most likely to get pregnant.

How birth control affects your ovulation and cycle

So, what is hormonal birth control?

Many women rely on hormonal birth control (AKA, birth control that contains hormones) for a number of reasons. But, hormonal birth control has a huge impact on your body. Just a small fluctuation in hormone levels can have profound effects; ranging from changing your metabolism, to dictating if you wanna get down and dirty, or get in your feelings. 

Hormonal birth control includes two hormones, estrogen and progestin. They are two hormones that play an essential role in the regulation of your ovulation cycle and reproductive system. Estrogen is a hormone that develops and maintains the "female" characteristics of the body—in a woman's cycle, it helps to produce an environment that enables the fertilization of an embryo. Progestin is a form of progesterone, a hormone that helps to regulate your cycle and get your body ready for pregnancy. 

Some forms of birth control have a mix of the two, estrogen and progestin, and others only have one, progestin. Since these hormones are the key orchestrators of your menstrual cycle, it makes sense that your ovulation would be different as a result of taking hormonal birth control.


Hormonal birth control can be split into two categories:

1. Estrogen and progestin combined hormonal birth control, including:

  • Oral contraceptive pill
  • Vaginal ring (Nuva ring)
  • Patch

2. Progesterone only hormonal birth control, including:

  • Hormonal intrauterine device (IUD)
  • Progesterone only pill
  • Injection 
  • Implant

Oh, we also have an article on picking the best birth control method for you—give it a read.


How birth control affects your ovulation and cycle

1. How estrogen and progestin combined birth control affects your ovulation 

The estrogen and progestin combined birth control works by releasing synthetic progestin and synthetic (or, sometimes bioidentical) estrogen into the bloodstream. The release of these synthetic hormones (in simpler terms, chemicals tricking your body into thinking they're progestin and estrogen) causes your natural estrogen and progestin hormones to be suppressed.

When your natural estrogen and progestin hormones are suppressed, no ovulation occurs, meaning your ovaries do not release an egg. This is because of two reasons: First, this suppression stops the hormonal fluctuation that occurs with a "normal" cycle. Second, these pretend hormones also cause changes in the cervical mucus and the lining of the uterus to keep sperm from joining the egg.


2. How progestin-only hormonal contraception affects your ovulation 

Progestin-only birth control helps prevent pregnancy in a few ways, by reducing the amount of natural progestin released in your body:

  • The mucus in the cervix thickens, making it difficult for sperm to enter the uterus and fertilize an egg.
  • It stops ovulation, but it does so inconsistently. About 40% of women who use progestin birth control will continue to ovulate.

In short: ovulation is still likely to occur with progestin-only options. While progesterone levels (the hormone that gets your body ready for pregnancy) may be suppressed to an extent, many users of a progestin-only form of birth control still experience hormonal fluctuations in line with a “typical” cycle. And, that cycle includes ovulation.


Bonus: How birth control impacts your period

TL;DR: It depends on what kind of birth control you use and how you use it.

Oral Birth Control Pills: These are the most widely used method for pausing your period. There are many different versions of the pill, which have been finessed to cause lighter-periods or no-period at all. 

The IUD: About half of the women who use a hormone-containing IUD stop having periods 6 months after it’s put in. For another 25%, periods happen less often, but don’t stop. The copper non-hormonal IUD does not interfere with your body's natural cycle or stop you from ovulating each month.

Patches and vaginal rings: These both work like birth control pills, with 21 days on their hormones and 7 days off. The 2-inch patch goes on your stomach, bottom, back, or upper arm. You should expect to get your period during those 7 days off of hormones. To pause your period, you’d attach another hormone-containing patch after 21 days. 

Vaginal rings are flexible plastic devices that contain the same hormones as a combination of birth control pills. To stop your period, you would leave the ring in place for 3 weeks, then replace it with a new one.

Shots: Birth control shots are one of the most effective ways to stop your period. At first, you may have a lot of bleeding. This eventually goes away, and the shots do a good job of stopping your period. Nearly 75% of women have no periods after a year of use.

Implants: Implants ease the bleeding that happens during your period. But, they only completely stop periods in less than 25% of those who have them.


How birth control affects your ovulation and cycle


Millions of women in the United States regularly use hormonal birth control. There are many different types of birth control available and they can impact a woman’s body and cycle in various ways. At Stix, we believe it is important for women to have all the information available to make their own choices about their bodies. 


When to take a pregnancy test if you're on birth control


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