10 Facts About Hormonal Birth Control and Your Health

In terms of effectiveness, hormonal birth control is a step up from other methods like condoms and spermicide if you don’t want to get pregnant. And you have a choice about how the hormones are administered, as well as the freedom to choose how quickly fertility returns after the birth control ends. In addition to preventing pregnancy, people use birth control for things like lessening premenstrual syndrome, controlling painful or heavy periods, and clearing up acne. Your doctor can help identify the birth control that best addresses your needs.

Estrogen and progestin are the two hormones found in birth control, used either in combination or as progestin-only, and the way they prevent pregnancy is different. What you want out of your birth control will help guide your choice, but so will your medical history. If you’re a smoker, have breast cancer, suffer from migraines with aura, or are worried about high blood pressure, blood clots, or kidney disease, your doctor will steer you clear of birth control that contains estrogen.

Two of the three progestin-only options happen to be some of the most effective at preventing pregnancy: IUDs and implants. An intrauterine device is shaped like a T and inserted into the uterus. It’s 99% effective, making it the most reliable birth control out there. Once it’s in, there’s not much you need to do, and there are generally fewer side-effects than estrogen-containing birth control. An IUD can last years, and removal is quick and easy. (There’s also a non-hormonal option that uses copper to decrease sperm motility and prevent implantation of an embryo.)

The other progestin-only option is an implant—a matchstick-sized flexible bar inserted in your arm just under the skin that’s effective for up to five years. IUDs and implants are called long-acting reversible contraceptives (LARCs). They’re so popular that a study in the journal Contraception found around half of ob/gyn residents who were on birth control used one of these methods. One reason women love progestin-only birth control: For many, their periods cease entirely while using these devices.

Progestin-only pills are highly effective, but the downside is you have to take them at the same time every day, explains Nicole Economou, M.D., a clinical instructor of ob/gyn and reproductive sciences at the University of California, San Diego. Unlike estrogen-containing pills that give you some leeway, if you miss a progestin-pill dose by even a few hours, you should use condoms for a couple days to prevent pregnancy. (The FDA just approved a new progestin pill that’s more forgiving in the timing.)

In a survey of 72.2 million women, 12.6% used oral birth control. Combined-hormone pills are formulated to give you a period either monthly or four times a year—or, you can get rid of it altogether. But although pills are popular, they’re not one-sized-fits-all. “I could give five women in a room the same pill, and they would have five different experiences,” says obstetrician and gynecologist Megan Evans, M.D., an assistant professor at Tufts University School of Medicine in Boston.

As long as you’ve been taking oral contraceptives for a while, with estrogen-containing pills, it’s not the end of the world if you miss a day: You should still be protected against pregnancy. Take two pills the next day, spaced out from each other. For example, if you take a pill normally at 8 a.m., take the makeup pill at 10 p.m. If you miss two days of pills, it’s still OK, but talk to your doctor just to be safe, Dr. Economou recommends.

If the idea of inserting something semi-permanent like an IUD or implant into your body concerns you, but taking a daily pill feels like way more hassle than you need, good news! A new combined-hormone patch has recently been approved by the FDA and provides the same level of protection as the traditional pill. To use it, simply apply the adhesive to your stomach, butt, or torso, and forget about it. (You will still need to change it once a week.)

In the first few weeks or months on a new birth control regimen, you may develop symptoms like nausea, spotting or breakthrough bleeding, breast tenderness, and headaches. In the long-term, birth control can help control heavy or prolonged periods, and reduce cramps and discomfort. Keep in contact with your doctor, updating them on how you’re feeling, but try to give it a cycle or two to let your body adjust. “It’s really easy to change your method if you’re unhappy,” Dr. Economou says.

Some women worry that hormonal birth control will increase the odds of developing breast cancer, but doctors say the likelihood is small. Meanwhile, “using birth control pills can actually reduce risk of ovarian and endometrial cancer,” says Dr. Evans. Even for patients who have a BRCA mutation that raises breast or ovarian cancer risk, docs recommend that they can continue using hormonal birth control but undergo cancer screening earlier. At the end of the day, birth control is a quality-of-life issue. Says Dr. Evans, “Even if there is a family history, typically, the benefits outweigh the risks.”