Breakthrough bleeding is any unscheduled bleeding you experience while taking oral contraceptives.

Breakthrough bleeding is a common side effect of birth control pills. It’s especially common in the first three months of using hormonal birth control. It may also happen after you switch to a different type of contraceptive or to a pill with a different estrogen dose.

Breakthrough bleeding is not usually a cause for concern, but sometimes it can be related to an underlying medical condition. Light spotting isn’t as worrisome as heavy or continuous breakthrough bleeding.

Take note of how much you bleed, when it happens, and how long it lasts. This information can provide important clues to help your doctor diagnose the cause of your bleeding.

A few factors can lead to breakthrough bleeding when you’re on the pill, including the type of pill you use and other medications you may be taking.

The type of oral contraceptive you use

Some types of birth control are more likely than others to cause breakthrough bleeding.

Combination oral contraceptives

Combination pills are the most commonly used type of oral contraceptive. They contain synthetic forms of the hormones progestin and estrogen.

These pills are available in different cycle lengths that determine how often you get your period. Cycles range from 28 days to months, depending on the type you choose.

Anywhere from 30 to 50 percent of people using combination birth control pills experience breakthrough bleeding in the first three to six months of use. This drops to 10 to 30 percent by the third month. Lower doses of estrogen are associated with more episodes of bleeding.

Progestin-only pills

Progestin-only pills, also called the minipill, contain progestin but not estrogen. They are most often prescribed to people who can’t take estrogen for health reasons, such as a history of deep vein thrombosis (DVT), or people over age 35 who smoke.

The minipill is continuous, meaning it consists of only active pills, so there is no break. You may not have a period while taking these pills, but some people do.

Breakthrough bleeding is the most common side effect of the minipill. The pattern of unscheduled bleeding is also more unpredictable with the minipill than with combined birth control pill.

It’s more likely to happen if you don’t take the pill at the same time every day. Missing your pill by just three hours significantly increases the risk of bleeding as well as the risk of pregnancy.

Your pill’s cycle

You’re more likely to experience breakthrough bleeding on continuous birth control. Continuous birth control pills, such as Yaz and Seasonale, contain only active pills that are taken continuously for three months or the minipill, which is taken continuously without a break.

How consistently you take it

A missed dose is a common cause of breakthrough bleeding on the pill. Remembering to take your pill every day may reduce or prevent episodes of breakthrough bleeding. If you’re using the minipill, it’s important to take it at the same time every day.

Smoking

According to the Mayo Clinic, people who smoke are more likely to have breakthrough bleeding on the pill than those who don’t. Smoking also significantly increases your risk of other complications on the pill, such as heart attack and stroke.

Starting a new medication or supplement

Starting a new medication or supplement can interfere with birth control and cause breakthrough bleeding.

medications that can cause breakthrough bleeding

Always speak to your doctor before starting a new drug or supplement. This is especially important if you are on the pill.

Vomiting or diarrhea

Persistent vomiting or diarrhea can prevent your body from absorbing the hormones in your birth control pill. This may cause spotting or cause your pill to be ineffective.

These symptoms are more likely to develop in people with gastrointestinal disorders such as irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD).

Breakthrough bleeding on the pill usually stops within three to six months of starting the pill. Episodes of bleeding can last longer if you are taking a continuous birth control pill or if you often forget to take your pill.

Breakthrough bleeding on the pill doesn’t mean your birth control is ineffective. Pregnancy is unlikely if you are consistently taking the pill as prescribed. If you have missed a dose or have symptoms of pregnancy, your doctor can perform a pregnancy test to rule it out.

Breakthrough bleeding on the pill is common, but it can sometimes be a sign of an underlying condition.

see your doctor if:
  • your bleeding lasts more than seven days in a row
  • your bleeding increases or is severe
  • you have pain in your lower abdomen or pelvis
  • you think you might be pregnant
  • you have a fever

Birth control pills can cause rare but serious side effects such as blood clots and stroke. Get emergency medical care if you experience:

  • significant bleeding
  • sudden severe abdominal pain
  • severe or sudden headache
  • pain in your chest, groin, or leg — especially your calf
  • pain, weakness, or numbness in your arm or leg
  • sudden shortness of breath
  • sudden slurred speech

The best way to stop breakthrough bleeding on the pill is to take your pill at the same time every day. For most people, breakthrough bleeding stops after three months of taking the pill as directed.

If you continue to experience unscheduled bleeding, speak to your doctor about other ways to stop spotting on the pill. Your doctor may prescribe a low-dose pill or supplemental estrogen.

Breakthrough bleeding on the pill is common, especially in the first few months of using the pill. It’s a bit of an inconvenience, but it’s not a sign that your pill isn’t working and it shouldn’t stop you from continuing to take the pill.

See your doctor if vaginal bleeding persists, if it’s accompanied by other symptoms, or if you missed a pill and think you may be pregnant.