Is taking Plan B a couple or even countless times bad for your long-term health? Here's what the experts say.

Susan Brickell
April 19, 2018

When your regular form of birth control fails—whether it’s a broken condom or missed oral contraceptive—taking the morning-after pill as soon as possible can help prevent an unplanned pregnancy. While it's perfectly safe to take the morning-after pill, should you be concerned if you've taken it more than once, or even countless times? And could it affect your ability to get pregnant in the future? We asked experts to weigh in.

The most common morning-after pills are over-the-counter tablets containing higher doses of levonorgestrel, a synthetic progestin hormone that is also in oral contraceptives. These pills work by preventing the ovary from releasing an egg, which in turn means you don't ovulate, lowering the risk of male sperm fertilizing an egg. You might know them by their brand names, such as Next Choice One Dose, Take Action, My Way, or the most well-known, Plan B One Step.

Important disclaimer: Although morning-after pills aren't 100% effective at preventing a pregnancy, they can reduce the risk by 75-89%, according to Planned Parenthood. If you have unprotected sex, you should take Plan B as soon as possible; they work best within the first three days after sex.

While the morning-after pill won't have harmful long-term effects on your body, taking it multiple times can turn your hormones upside-down, says Sherry A. Ross, MD, a Los Angeles-based ob-gyn and author of She-ology ($26; amazon.com). "It’s temporarily harmful in that you will have irregular bleeding and may feel emotionally unraveled," she tells Health. "But once you stop taking it, your body will have the opportunity to reset."

Orlando-based ob-gyn Christine Greves, MD, a fellow of the American Association of Obstetrics and Gynecology, agrees with Dr. Ross. You might experience unpleasant side effects after taking Plan B, she explains, including nausea and lower abdominal cramps in addition to irregular bleeding. But she stresses that these are short-term effects.

Although taken less often, Ella, another type of morning-after pill available with a prescription, also won't have long-term effects on your health, says Dr. Greves. But she does note that you shouldn't take other forms of birth control pills that contain progesterone for at at least five days after using Ella, because it could interfere with the pill's effectiveness.

However, if you've taken the morning-after pill for the umpteenth time, you might want to speak to your gynecologist about alternate contraceptive options, says Bat-Sheva Lerner Maslow, MD, a reproductive endocrinologist at Extend Fertility, pointing out that it's better to have a reliable form of contraception than constantly turning to emergency ones. If you struggle to remember to take birth control pills, for example, long-term contraception such as an intrauterine device (IUD) can make forgetfulness a non-issue. A copper IUD, for example, "is more than 99.9% effective at preventing pregnancy, and can be kept in for up to 10 years."

So, say you had unprotected sex and took the morning-after pill. Would that same pill prevent pregnancy if you then had unprotected sex again a few days after taking it? (Hey, accidents happen.) To play it safe, it’s best to take Plan B after every unprotected sexual encounter, experts say.

"In theory, it should cover you until your next period because of the changes it causes in the uterine lining," says Dr. Maslow, "but I wouldn’t necessarily recommend relying on it as a proactive form of birth control."

And can taking Plan B make it difficult to get pregnant when you do want to down the road? Fortunately, all experts we polled were in agreement on this: The morning-after pill won't have any long-term affects on your future fertility. Phew!