What Happens To Your Body When You Change Your Birth Control Pills

According to the Centers for Disease Control and Prevention (CDC), more than 12% of women of reproductive age use birth control pills at any given time, and they do it for a variety of reasons. Of course, the most common reason is to prevent pregnancy, but many women also take the pill to regulate their periods, alleviate period pain, or treat endometriosis or even acne (per Guttmacher Institute).

Just as there are many reasons a person may be inclined to take birth control pills, there are many different brands out there to choose from. Sometimes, a person may want to switch to a different brand that offers more non-contraceptive benefits such as acne relief. As Verywell Health points out, a person may also want to control their periods by switching to an extended cycle pill. Otherwise, a person may want to switch brands simply because their current brand gives them side effects that don't go away after a few months. Of course, any decision to switch brands should be made with the input of one's doctor.

What happens to your body when you switch birth control pills depends largely on the type of switch you are making. If you switch from a combination pill to a progestin-only pill ("mini-pill"), your body will be receiving less progestin and will no longer be receiving estrogen, according to Mayo Clinic. Even if you switch between combination pills, different brands contain different hormone doses, adds Verywell Health.

Either way, don't be surprised if you experience mild side effects for a few weeks or months as your body adjusts to a new pill. The changing hormone levels may lead to headaches, nausea, and breast tenderness, but these should all go away within a few months (per Healthline).

If you switch from a combination pill to a progestin-only pill, you may be more vulnerable to pregnancy. Progestin-only pills are thought to be somewhat less effective than other pills, says Mayo Clinic. On the other hand, the American Academy of Family Physicians notes that progestin-only pills often have fewer side effects, and less than 3% of women get pregnant if they take the pills correctly.