Why Am I Bleeding Between Periods On The Pill?

If you take birth control pills and notice bleeding between periods, you are not alone. This is one of the most common reasons people call their doctor. The medical term is breakthrough bleeding. It is usually not dangerous. But it is frustrating and can be worrying. Here is what actually happens inside your body and what the evidence says about why it happens and what you can do about it.

What Exactly Causes Breakthrough Bleeding on the Pill?

Birth control pills work by giving your body a steady dose of synthetic hormones. These hormones keep your uterine lining thin. A thin lining means less tissue to shed during your period. But sometimes that lining becomes unstable. When it is unstable, small bits of it can break away at the wrong time. That is the bleeding you see.

Research published in the journal Contraception has found that breakthrough bleeding is most common in the first three to six months of taking the pill. Your body is adjusting to the new hormone levels. For many women, it stops on its own after that adjustment period. If it continues beyond six months, something else may be going on.

Studies have also shown that low-dose pills are more likely to cause breakthrough bleeding than higher-dose pills. Many modern pills contain only 20 micrograms of estrogen. Older pills had 35 or 50 micrograms. Less estrogen means a thinner lining, but also a more fragile one.

Is the Bleeding a Sign the Pill Is Not Working?

This is the question most people really want answered. The short answer is no. Breakthrough bleeding does not mean the pill is failing to prevent pregnancy. The pill prevents pregnancy mainly by stopping ovulation. Bleeding between periods does not mean ovulation is happening.

According to the American College of Obstetricians and Gynecologists, breakthrough bleeding is a common side effect, not a sign of failed contraception. You are still protected as long as you take your pills correctly. Missing pills is a different issue. If you miss pills and then have breakthrough bleeding, that is a sign you may have ovulated. That situation is different.

One non-obvious point many people miss: the bleeding you see during your placebo week is not a real period. It is withdrawal bleeding from the hormone drop. Breakthrough bleeding during active pills is also withdrawal bleeding, just from a smaller hormone fluctuation. Your body is not having a menstrual cycle in the traditional sense.

What Are the Most Common Reasons for Breakthrough Bleeding?

Several factors can trigger breakthrough bleeding. The most common reason is simply your body adjusting to the pill. But there are other causes worth knowing about.

• Missing pills or taking them late. Even a few hours can cause a hormone dip that triggers bleeding. Set a daily alarm if this is an issue.
• Smoking. Smoking affects how your liver processes estrogen. Smokers have higher rates of breakthrough bleeding. This is another good reason to quit.
• Certain antibiotics and other medications. Rifampin, an antibiotic for tuberculosis, is the only antibiotic proven to reduce pill effectiveness. But some seizure medications and the herb St. Johns Wort can also cause breakthrough bleeding.
• Vomiting or diarrhea. If you have a stomach bug, your body may not absorb the pill fully. Use backup contraception for seven days after you recover.
• Infection or cervical irritation. Sexually transmitted infections like chlamydia can cause bleeding. So can a cervical polyp or even rough sex. If the bleeding is new and you have other symptoms, get checked.

When Should You Actually Worry About Breakthrough Bleeding?

Most breakthrough bleeding is harmless. But some situations need a doctors attention. The table below shows when it is likely a normal side effect and when it could signal something else.

If you ever soak through a pad or tampon in an hour for several hours in a row, that is not breakthrough bleeding. That is heavy bleeding. Go to urgent care or the emergency room. Also get help if you feel dizzy, faint, or have severe pelvic pain.

What Actually Works to Stop Breakthrough Bleeding?

If the bleeding bothers you, there are evidence-based steps you can take. The first is patience. Studies have found that about 50 percent of women who have breakthrough bleeding in the first three months see it resolve by the sixth month without any change.

If you do not want to wait, talk to your doctor about switching pills. A 2018 review in Cochrane Database of Systematic Reviews looked at different ways to manage breakthrough bleeding. The strongest evidence was for switching to a pill with a higher estrogen dose or a different type of progestin. Pills containing drospirenone or norgestimate may cause less breakthrough bleeding for some women.

Some doctors suggest taking your pills at the exact same time every day. This is good advice for preventing pregnancy, but the evidence that it specifically reduces breakthrough bleeding is weak. It may help for some people but not everyone.

There is one trick that does have some evidence behind it: taking an extra low dose of estrogen for a few days. This is called supplemental estrogen. It can stabilize the lining. But this is not something you should do on your own. Ask your doctor if it is an option for you.

Ibuprofen taken at anti-inflammatory doses may also reduce bleeding. Some studies have shown that 400 to 800 mg three times a day for a few days can help. But do not take ibuprofen long term without a doctors approval. It can cause stomach and kidney problems.

Common Misconceptions About Breakthrough Bleeding

There is a lot of bad information online about this topic. One common myth is that breakthrough bleeding means your body is building up toxins or that you need to detox. There is no evidence for this. Your body does not need to detox from birth control pills. The bleeding is a physical response to hormones, not a sign of toxicity.

Another myth is that you should stop taking the pill for a few days to let your body reset. This is dangerous. Stopping the pill can cause ovulation. You could get pregnant. It can also make the bleeding worse when you restart. Never stop your pill without talking to your doctor first.

Some people believe that taking the pill continuously without a break will stop breakthrough bleeding. This is actually the opposite of what often happens. Continuous use can cause more unpredictable bleeding in the first year. It works well for some women but not all. The evidence shows that taking a four-day or seven-day break every three months may actually reduce breakthrough bleeding for women on continuous regimens.