Headaches are widely viewed as a common side effect of birth control pills. But is the pill itself to blame for your headache?

To understand why your head hurts and how to prevent it, you need to understand how birth control pills work and what effect they have on your body’s hormones.

Birth control pills, also known as oral contraceptives, prevent pregnancy by changing the way your body releases hormones.

Hormones are powerful chemicals that your body uses to function. Organs called endocrine glands create them. These include your pituitary gland, thyroid, and pancreas.

Birth control pills prevent pregnancy from happening by preventing the release of estrogen, which prevents an egg from being released.

They thicken the cervical mucus, which makes it harder for sperm to reach an egg that may have been released.

Birth control pills also thin the lining of your uterus, which prevents a fertilized egg from attaching to it.

The two main kinds of birth control pills are the combination pill and the progestin-only pill.

Combination pills

These contain two synthetic hormones called estrogen and progestin. The hormones work together to keep your body’s estrogen levels steady. This stops ovulation and the release of a mature egg. The combination pill also changes the cervical mucus and uterine lining to help prevent pregnancy.

Combination birth control pill packs usually come in packs of 21 or 28 pills. Each pack has 21 active pills containing hormones. With a 21-pill pack, you take the birth control pill every day, once per day, for three weeks. On the fourth week of the month, you take no pills. Menstrual bleeding will occur during this one-week break.

Birth control packs containing 28 pills follow a similar pattern. Instead of taking a one-week break every month, you take one week of inactive or reminder pills which are placebos. The inactive pills don’t contain any hormones. These pills are meant to make it easier for you to remember to take your birth control pill by maintaining the daily habit.

Combination birth control pills also come in a continuous dose option. This option can reduce the number of periods you have from 12 to 13 per year to four or less per year.

Progestin-only pills

As their name suggests, these pills only contain the hormone progestin. They’re also called minipills. Minipills contain less progestin than combination birth control pills. The hormone focuses on altering your body’s cervical mucus and uterine lining to prevent pregnancy. Because these don’t contain estrogen, progestin-only pills only sometimes prevent ovulation.

Progestin-only pill packs don’t contain inactive or reminder pills. You take the minipill every day. These may be a better option for you if your body can’t tolerate estrogen.

Fluctuations in hormone levels caused by the menstrual cycle can trigger headaches for some people. For some of these people, birth control pills can actually help reduce how painful these headaches are and how often they occur. This is because the pills can even out their estrogen levels.

Others may find that the drop in estrogen that accompanies menstrual bleeding can cause or worsen their headaches.

Birth control pills aren’t strictly to blame for this. Whether you’re taking birth control pills or not, the reduction in estrogen that accompanies menstrual bleeding may put your body into a kind of hormonal withdrawal.

Both combination birth control pills and progestin-only pills may cause headaches as a side effect. Additional side effects of birth control pills may include:

  • breast tenderness
  • nausea
  • high blood pressure
  • irregular menstrual bleeding or spotting between
  • weight gain or loss
  • acne
  • other skin reactions
  • fatigue
  • depression
  • changes in libido

Birth control pills may also trigger symptoms in people with asthma.

Birth control pills aren’t recommended for people 35 years or older who smoke, or for people who have high blood pressure or certain blood-clotting disorders.

You should also talk to your doctor about any potential risks if you:

  • are breast-feeding
  • have a history of breast cancer
  • have a history of diabetes-related complications
  • take certain anticonvulsants medications
  • take certain antituberculosis medications
  • take certain medications for HIV
  • take certain medications for AIDS
  • take St. John’s wort
  • have a history of migraines with aura

Rare but serious additional health risks can include:

  • a stroke
  • a heart attack
  • gallbladder disease
  • liver tumors
  • blood clots

The risk of stroke may be increased further if you experience migraine headaches with aura while taking the combination birth control pill.

Birth control pill use may increase the risk of cervical cancer. More research is needed to clarify the role of birth control pills in developing cervical cancer. The birth control pill may also decrease the risk of other reproductive cancers, such as ovarian and endometrial cancers. Breast cancer risk due to birth control use is unclear.

Birth control pills don’t protect against sexually transmitted infections, so you should use a barrier method during sexual activity.

Taking your birth control pill at the same time every day may help reduce side effects. This is because your hormone levels remain steady. If you take a pill early one morning and then take one again in the afternoon the next day, it creates a gap between doses. This can cause a shift in your hormone levels and may prompt a headache. It can also lower effectiveness and increase your risk of pregnancy.

Taking over-the-counter (OTC) or prescription pain relievers before menstruation begins may also help prevent symptoms before they occur.

Treatments that may help reduce headaches once they occur include:

  • OTC painkillers, such as naproxen or ibuprofen
  • prescription pain relievers
  • ice packs applied to your head or neck
  • biofeedback
  • acupuncture

Read more: Is it OK to miss a day of birth control? »

Birth control pills are generally safe, effective, and well-tolerated. People who don’t smoke should be able to take birth control pills until menopause or until they no longer need them.

Negative side effects caused by taking birth control pills, including a headache, generally lessen or go away in a few months. Positive side effects may include relief from common menstrual symptoms such as cramps or heavy bleeding, improved skin, and a lower risk of certain cancers.

Talk to your doctor about the ways you can adjust your medication if your birth control pills seem to be causing your headaches. Together, you can work to prevent or reduce this hormone-related side effect.

This may be possible by:

  • switching to a low- or lower-dose birth control
    pill, which contains less estrogen and minimizes the drop in hormones on break
    or placebo days
  • switching to a continuous dose birth control
    pill, which reduces or eliminates break or placebo days
  • reducing the number of break or placebo days in
    your regimen
  • switching from combination to progestin-only pills,
    which don’t contain estrogen
  • increasing supplementation of estrogen on break
    or placebo days by wearing an estrogen patch

No two people respond the same way to birth control pills. Finding the right birth control method for you may require some trial and error. Talk to your doctor about the pros and cons of each option to determine what methods will work best for both your body and your lifestyle.

Learn more: Which birth control is right for you? »