Woman sitting on the edge of the bed and having menstrual cramps

5 Ways Birth Control Can Affect Your Period

Laylah Funk

Hormonal birth control is so much more than just protecting against pregnancy. In fact, more than half of women in the United States are on some type of hormonal birth control—using it to treat acne, symptoms associated with endometriosis, PCOS (aka, polycystic ovary syndrome), and—you guessed it—to regulate periods. If you’ve ever been on birth control, you probably know that regardless of what you’re using it for, it’ll probably have some sort of an impact on your period—and that’s totally normal. Here’s what to keep an eye out for.

Spotting, Irregular Bleeding, and Breakthrough Bleeding

Unexpected spotting is actually super common when you’re on any type of hormonal birth control—especially if you’re in your first couple months of using it and you’re still adjusting to the brand-new hormone levels in your body. Doctors aren’t actually 100% sure why this happens so frequently, but one theory is that the changes in your uterine lining brought on by the increase in hormones causes some light, minor bleeding at first. If you’re on the pill, forgetting to take it for even just 1 day can cause some spotting, too.

Experiencing spotting while on birth control is ~usually~ nothing to be concerned about, especially if your body is still adjusting to the changing hormone levels. But if you experience frequent spotting or irregular bleeding after having been on the same birth control for a few months, it’s always best to check in with your doctor just in case.

More Manageable Cramps

If you’re a longtime menstruator, you’ve probably experienced period cramps painful enough to, at the very least, keep you in bed despite having other plans. Basically, when you ovulate, the lining of your uterus thickens to nourish any potential fertilized eggs. Without a fertilized egg, your uterus will contract to shed that lining—which is what causes the pain you know as cramps.

Hormonal birth control actually works by preventing you from ovulating: It thins the lining of your uterus, causing less painful and intense contractions it’s “shedding’ during periods. That’s why when it comes to treating severe cramps, Dr. Kecia Gaither, MD in OB/GYN & Maternal Fetal Medicine at NYC Health, recommends combination contraceptive pills that have both estrogen and progestin, because they’re more consistent than progestin-only pills at preventing ovulation. “Progestin-only pills are ideal for women who are breastfeeding, or who can’t take estrogen, like breast-cancer patients,” Dr. Gaither says. “They’re slightly less effective than combination pills.”

Shorter & Lighter Periods

For the same reason period cramps tend to be a little less intense when you’re on hormonal birth control, your periods could end up being shorter and lighter, too! When the lining of your uterus (called the endometrium) is thinner, there’s less to shed during ~that time~ of the month, which can result in a slightly shorter and lighter period! Two birds, one stone.

Less Frequent Periods

There are actually a handful of hormonal birth controls that will either delay your period or reduce their frequency—and they’re usually continuous-use birth controls. When using continuous-use birth controls, you take the active hormones for a year or longer without any breaks—meaning you don’t experience the “withdrawal bleeding,” or the period, that you’d typically experience while using extended-use birth controls.

Basically, you have a lot of options—including not having a period at all. “With some pills, you take them every day for three weeks, then wait a week before starting a new pack—and that’s when you get your period,” Dr. Gaither says. “With others, you can take the pill every day for three months, and you only get your period four times a year. Some pills you can take for a year straight without getting a period.”

Withdrawal Bleeding

You know how on Period Week of your birth control pill pack, there’s that row of pills that are a different color than the rest of the pack? Those pills are commonly referred to as the “inactive pills,” and they actually don’t contain any hormones (or, if they do, it’s a small amount). The lack of hormones in those pills are actually what causes you to bleed—it’s your body withdrawing from the hormones that it got used to during the rest of the month. And yes, that means the “period” you get every month while taking a combined hormonal contraceptive pill isn’t actually a true period—as much as it might feel like one. It’s called withdrawal bleeding

Basically, combination birth control pills are effective as a contraceptive because—when taken correctly—they keep you from ovulating. Things you can’t do without ovulating include: 1) Get pregnant, and 2) Get a period. So if you’re wondering why the “period” you get when you’re on the pill is a little different than the period you’re used to—if it’s lighter, shorter, less painful, more regular, easier to predict—now you know why. In fact, a lot of people choose to go on the pill for those very reasons!

No matter what you’re using hormonal birth control for, it’s always best to consult with your doctor about your goals, symptoms, side effects, and concerns. What works best for you might not work best for someone else. Honestly, what worked best for you only a couple years ago might not even work for you now. Different birth controls can affect everyone’s bodies very differently, but your OB/GYN can help you to figure out what’s best for you—and your period.