Side Effects of Birth Control Pills, Common and Not So Common

Birth control packets

Birth control pills come in two types, combined oral contraceptives, and progesterone-only forms. Progesterone-only pills are not used very often as they are reserved for special circumstances. Therefore the combined pills will be the focus of this discussion.

All combined pills have the same estrogen in them, just at different doses. The progesterone in them has many versions so that if someone has side effects, they can be tailored to any problem. They work by not allowing ovulation from the estrogen component and stabilization of the lining of the uterus by the progesterone component.

The most common side effects of birth control pills

  1. Bleeding at the wrong time. This can be bleeding between periods as well as skipping periods. The solution is not to worry but work with your doctor in finding the levels of hormones that work for you.
  2. Nausea. This is common, especially during the first few weeks of taking the pill. Usually, it goes away in a week or so and we recommend taking the pill at night for a few weeks so that you are asleep and feeling nausea until it goes away.
  3. Breast tenderness. This is also common and usually clears up in a few cycles. Sometimes a progesterone change is indicated. 
  4. Weight gain. There can be mild weight gain on a pill due to holding fluid. The research just does not show that pills have any significant weight gain. All studies show 1-3 lb weight gain that is not permanent. Once again stopping the pill should make any weight gain go away within 48 hours. That is the time it takes for the medication to go out of your system. Once again this can be an indication to change the progesterone.
  5. Moodiness. Some people have mood fluctuations on the pill and once again your doctor can change the pill for you to account for that.
  6. Dry eyes. Some people find they get dry eyes especially if they wear contact lenses. A mild saline eye drop would fix that.
  7. Lowered libido. This can be caused by the estrogen component, so a super low-dose pill may work. Otherwise, a nonhormonal option such as an IUD or barrier method may work better.

Serious but rare side effects or birth control pills:

 These side effects are a reason to contact your doctor as soon as possible:

  1. Migraine headaches. An occasional headache is not a problem but severe or frequent headaches are a problem. You should stop your pill and contact the doctor who may want to do more testing 
  2. Calf pain or swelling. If calf pain or swelling especially if it is one-sided and even more so if it occurs after a recent airline flight could indicate a blood clot also known as a deep vein thrombosis (DVT) can be very serious. This condition often runs in families so if your family has a history of blood clots some extra blood testing may be needed to make sure you are not carrying any genetic markers that may put you at risk.
  3. Increased blood pressure. Pills can cause an increase in blood pressure which is why you need to be seen at least once a year for a blood pressure check. Which is also why they are not over-the-counter medications. High blood pressure can cause all kinds of problems including cardiac disease and strokes.

High blood pressure can be a cause of headaches, but most of the time there are no symptoms.

Overall most women who take the pill do just fine and the pill has a few other benefits:

  1. Mild to moderate acne control. It usually takes about 4 months of taking them to kick in completely.
  2. Shorter, lighter periods that help women with a history of menstrual cramps enormously. In fact there are pills that can safely stop the period or bring it down to 4 light periods a year.
  3. Ovarian cancer protection. 5 years of combined oral contraceptives at any time in life lower ovarian cancer rates by nearly 90%. Women with a family history will often take them for prevention.

This is a list of side effects both common and possibly annoying but not serious and a section on possible serious and rare side effects. 

Of course, any questions can be and should be discussed with your doctor.

Author: Shannon Hudson MD

Medically Reviewed By

Sarah Adamic, NP
Women’s Health Nurse Practitioner