What is the birth control pill?
Birth control pills are a hormone-based medication taken mainly to prevent pregnancy. In the U.S., approximately 25% of women ages 15 to 44 take birth control pills (referred to as “the pill”). Some women also take the pill to help control certain conditions that are affected by hormones, such as migraines, heavy or irregular periods, and endometriosis.
The most common type of oral contraceptive pill contains estrogen and progestin (synthetic progesterone), which prevent pregnancy by stopping the ovaries from releasing eggs. They also make it harder for sperm to reach an egg and fertilize it.
They’re available in low dose (35 micrograms or less of estrogen) and ultra-low dose (20 mcg of estrogen or less). Depending on the one you take, you may get a period every month, every 3 months, or not at all. Pills that limit the number of periods you get or eliminate your periods are called continuous birth control pills.
Another type of pill is a progestin-only pill, known as a “minipill.” It works by preventing sperm from reaching an egg, though it sometimes stops the ovaries from releasing eggs.
Birth control pills can cause side effects, particularly during the first few months of being on them. Fortunately, the side effects of today’s pills are milder than they were in the past. Earlier versions of the pill contained much higher doses of hormones.
Side effects such as nausea, headaches, and breast tenderness were more common and severe, and there was a very small but serious risk of heart attack or stroke. The dosage of hormones found in today’s birth control pills is much lower, and the pills are considered to be relatively safe. Very serious side effects are rare.
Discuss with your doctor what you are looking for in birth control. Each birth control method has its most common side effects—it may even be positive. For example, some people love the side effect of improved acne on combination birth control pills. —Dr. Tara Kumaraswami
Most common side effects of the pill
Spotting, also referred to as breakthrough bleeding, is common and can occur during the first 3 or 4 months after you start taking the pill. It’s more common if you take progestin-only or continuous birth control pills or if you smoke.
Experts aren’t sure what causes breakthrough bleeding, but it may be that it takes time for your body to adjust to the hormones and the hormones make the lining of the uterus thinner.
Spotting can occur for other reasons. For example, you may notice spotting if you’re taking another medication or supplement, you miss doses, or you have diarrhea or vomit (all of these can interfere with your body’s ability to absorb the pill).
You can help prevent spotting by taking the pill at the same time every day. Breakthrough bleeding is usually very light, but if spotting is heavy enough to stain your clothing, try wearing a thin panty liner until it is no longer a problem.
If you’ve been on the pill for more than 6 months and still have spotting, see a doctor. You may need to switch to a different pill. Or, if you are taking a continuous pill, your doctor may recommend a brief break from the medication. This allows you to have a short period, which may stop the spotting.
2. Skipped periods
Birth control pills may cause you to skip periods because they help prevent pregnancy by thinning the lining of your uterus. Sometimes, the lining becomes so thin that there’s nothing to shed, so you don’t get a period.
Missed periods aren’t a cause for concern unless you’re experiencing early signs of pregnancy, such as fatigue, nausea, and increased urination.
Patients are most often bothered by changes in their bleeding patterns or early side effects like nausea or vomiting. —Dr. Kumaraswami
3. Breast tenderness
The hormones in birth control pills often make breasts feel more tender and sensitive, and can also cause swelling and tingling in the breasts. Estrogen and progestin have stimulating effects on your breasts, increasing the size and number of ducts and milk glands they contain and causing water retention.
You are most likely to notice breast tenderness just before your period starts. It usually goes away after a few months.
Wearing a bra with extra support can help. You can also take ibuprofen. If the soreness is intense or lasting, your doctor may recommend skipping the pill-free week or trying a different type of birth control.
4. Weight gain
Many women worry about gaining weight on the pill. This was a side effect of the earlier versions of the pill, which contained high levels of hormones. (Estrogen tends to increase fluid and water retention, while progesterone can increase your appetite.)
But today’s birth control pills contain much lower levels of hormones, so weight gain—if it occurs at all—is minor. A review published in the Cochrane Database of Systematic Reviews showed that taking combination birth control pills had no major effect on weight. Results of a separate review of 22 studies of progestin-only pills published in the same journal showed similar results.
If you do gain a few pounds in the first weeks and months after you start taking the pill, don’t panic. It’s usually temporary and is probably the result of water retention, not increased body fat.
Estrogen can irritate the lining of your stomach, causing nausea, particularly if the pill contains a higher dose of estrogen. Nausea usually goes away once you’ve been on the pill for 3 to 4 months. But if it continues, talk to your doctor. Switching to a progestin-only pill or a combination pill that contains less estrogen may be helpful.
If you experience nausea after starting the pill, try taking it at mealtime or at night with a snack. Home remedies, such as ginger tea or acupressure, are also helpful.
6. Headaches & migraines
If the ups and downs in your hormone levels give you headaches or migraines, taking birth control pills could reduce their severity and frequency because they even out your estrogen levels. But for others, the pill can cause or worsen headaches and migraines.
The pain usually occurs during the week you take inactive (placebo) pills and get your period, which is when your estrogen levels drop.
Headaches tend to lessen or disappear after a few months of taking the pill. You may be able to avoid headaches by taking the pill at the same time every day and by taking over-the-counter or prescription pain relievers before your period starts.
If you get more frequent or worsening migraines on the pill, see your doctor. You may need to switch to a different type of birth control. If you develop migraines with an aura, such as spots in your vision, it is important to speak to your doctor. Your doctor may recommend stopping the pill.
7. Mood changes
In some cases, starting the pill can improve your mood. But studies have found that for 4–10% of users, the pill has negative effects on mood, and the risk may be higher among those who are 19 or younger, take a progestin-only pill, or already have a mood disorder. Some people complain of mood swings, anxiety, and depression.
While experts don’t know exactly why the pill can cause mood swings, one theory is that the synthetic hormones can affect your body’s levels of feel-good hormones such as serotonin and dopamine. Some women may also be particularly sensitive to changing levels of estrogen and other hormones.
Lifestyle changes, such as exercising more regularly and following a healthier diet, may help with mild to moderate mood swings. But if you’re depressed, lethargic, or have other symptoms that are affecting your everyday life, see your doctor.
8. Decreased libido
If you take the pill, you may experience decreased sex drive. The pill can lower levels of testosterone, the hormone that enhances your libido. In most cases, the drop in testosterone isn’t enough to affect your sex drive, but you may be more likely to have a low libido if you had lower testosterone levels to begin with.
If the problem continues, talk to your doctor about switching to a pill that doesn’t lower testosterone levels or using a form of birth control that doesn’t contain hormones.
9. Changes in vaginal discharge
Some women on the pill experience more white vaginal discharge or changes in their discharge, such as an increase in thickness, particularly during the first few months of use. This usually goes away and isn’t anything to worry about, unless you have other symptoms, such as pain or burning in and around the vagina.
Women who take the pill may be more likely to develop yeast infections because it alters the natural levels of estrogen and progesterone, which can lead to yeast overgrowth.
You can lower your risk of developing yeast infections by making lifestyle changes, such as getting more sleep, eating less sugar, and changing your tampons and pads more often. If you experience chronic yeast infections, your doctor may recommend switching to a different method of birth control.
Long-term side effects and risks of the pill
If you’re generally healthy, you can safely take birth control pills for as long as necessary or until you go through menopause. But there are some serious risks of using the pill that, while uncommon, should be discussed with your doctor. These include:
Heart attack and stroke. A study published in The New England Journal of Medicine found that women who took combination pills with an ultra-low dose of estrogen had a 50% increase in risk of blood clot-related heart attacks and strokes, and the increase was higher (80%) in women who used low-dose combination pills. (Progestin-only pills did not increase risk of heart attack or stroke.) Still, the overall chance of having a heart attack or stroke is very low for most women, especially those under 35.
Breast cancer. Results of a study published in The New England Journal of Medicine showed that current and recent birth control pill users had a slightly higher risk of breast cancer than women who had never taken birth control pills. The risk decreases once you stop taking the pill. Once you’ve been off the pill for 10 years or more, your risk of breast cancer returns to the same level as if you’d never taken it.
Cervical cancer. Taking the pill slightly increases your risk of cervical cancer. But your risk eventually returns to normal once you stop taking them, according to the American Cancer Society.
Fertility is not at risk. Women sometimes worry that the pill could make it harder to get pregnant once they stop using it. But women who have taken the pill are just as likely to conceive as women who never used it.
Risk factors for taking birth control
Before you start taking birth control pills, your doctor will go over your medical history to make sure they’re safe for you. Women with a history of the following should not use a combination pill:
- Blood clots
- Breast cancer
- Heart problems
- Migraines with aura
- Liver disease
- People who have recently undergone bariatric surgery (the procedure may interfere with your ability to absorb the pill properly)
- Over 35 and smoking
How to reduce side effects from birth control
Side effects from the pill usually go away on their own once you’ve been on it for a few months and your body adjusts to the medication. While you may not be able avoid all side effects, you may be able to reduce the chance of getting others, such as nausea and headaches, by:
- Taking the pill at the same time every day.
- Taking it at mealtime or at night with a snack.
- Taking an over-the-counter or prescription pain reliever for a few days before your period starts.
If any side effect of the pill continues and is affecting your quality of life, talk to your doctor about switching to a different pill or another method of birth control.
Just because you start one form of birth control does not mean you must stay on it. Your friend or cousin may have one experience with a birth control, but yours could be very different. You can always ask to change your method. —Dr. Kumaraswami
Birth control types and side effects
Depo-Provera. Some people stop using this injectable form of hormonal birth control because it can cause prolonged spotting or bleeding and weight gain. Plus, it can take up to a year after stopping the shots to get back your fertility (be able to get pregnant).
IUDs. Over time, hormonal IUDs may cause amenorrhea (loss of your period). The non-hormonal (copper) IUD, ParaGard, may cause heavier and more painful periods.
The pill. Common side effects include nausea and breakthrough bleeding.
Birth control implant (Nexplanon). This method can cause changes in bleeding, such as breakthrough bleeding and irregular cycles. It may not work as well in women who have a BMI above 30.
Birth control patch. You may develop irritation in the area it’s applied.
Vaginal ring (NuvaRing, Annovera). Rings can cause an increase in vaginal discharge.
Side effects of the birth control patch
Side effects of the patch are similar to that of the birth control pills. But women who use the patch may develop irritation of the area where they apply it. The patch also has an increased risk for blood clots in women who are obese (with a BMI over 30). And it may be a less effective method of birth control for women who weigh over 198 pounds.
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