Another day, another Internet myth about women’s health that needs to be debunked. In our post-Roe world, where abortion and birth control access are under very real threat, it’s essential that we dispel this one. The myth in question is about Plan B — according to several people on social media, this emergency contraceptive can cause infertility.
One TikTok, for example, features a creator pretending to pop multiple pills as the text overlay reads “Finding out that taking a certain amount of Plan B can make you infertile.”
The TikTok is clearly a joke (the creator clarifies that she’s popping fruit snacks in the comments of her video), but the impact of content like this is real. It’s especially crucial that we get things right on social media platforms like TikTok, which is where many teens find information on sexual and reproductive health — because in many cases, they don’t have a trusted adult they can talk these issues through with, and sex ed in the United States is completely broken.
Medical misinformation creates fear and confusion — to the point that, in this particular case, many people may avoid taking emergency contraception after unprotected sex for fear of infertility down the line.
So is there any element of truth to the idea that Plan B use can affect fertility? We’ve tapped Jessica Ryniec, MD, a reproductive endocrinologist, to break it down.
First things first: How does Plan B work?
Colloquially, we use the term Plan B or “the morning after pill’ to describe emergency contraception. Plan B is the name of one emergency contraception product, but Preventeza, AfterPill, My Choice, are some examples of other "morning after pills", according to Planned Parenthood.
How exactly does it work to prevent pregnancy? By delaying ovulation.
“Plan B is an emergency contraceptive pill that contains a powerful progesterone that delays ovulation,” says Dr. Ryniec.
Timing is key for these pills to work.
“It needs to be taken within 72 hours (the earlier the better) after unprotected intercourse to prevent an egg from being released from the ovary. It may also make the uterine lining less receptive to a fertilized egg preventing implantation but it's primary action is through delaying ovulation, so that the egg is not there to meet the sperm,” says Dr. Ryniec.
Does Plan B alter a person’s hormones?
Yes, according to Dr. Ryniec. There’s certainly a lot of buzz out there about hormone health, and people may hear this and immediately panic about emergency contraception’s overall effect on a person’s hormonal function. But this effect doesn’t have long-term reach.
“It temporarily alters hormones to prevent ovulation, but since it is not intended for long term/regular use the altered hormones are not lasting,” says Dr. Ryniec.
So, will Plan B affect your menstrual cycle?
It will — the mechanism of pregnancy prevention is all about delaying ovulation, which does change a person’s following cycle.
“One would expect to get their period later than typical if the Plan B successfully delayed ovulation,” says Dr. Ryniec. “This would mean the cycle you take Plan B in could be longer.”
Menstrual irregularities happen, but only as long as you’re taking emergency contraception.
Emergency contraception is just that — contraception that should be taken in emergency situations. It is not a primary form of birth control, and should not be used every month. When taken, emergency contraception will change a person's menstrual cycle, so if it is taken over multiple cycles, it can lead to more irregularities.
“Overuse of plan B can lead to irregular menstrual cycles (while using it) due to its impact on ovulation,” says Dr. Ryniec.
Are there risks associated with taking emergency contraception repeatedly?
“Plan B is designed for occasional/emergency use, not regular contraception, so if someone finds that they need emergency contraception frequently it is a good idea to discuss a more reliable/long-acting contraceptive plan with a healthcare provider,” says Dr. Ryniec.
With that being said — and contrary to the social media discourse — repeated use does not lead to infertility.
“There are no direct health or fertility impacts from Plan B,” says Dr. Ryniec.
There’s one thing Plan B doesn’t address.
Plan B can prevent pregnancy, but there’s one thing people need to keep in mind about its limitations.
“One must [also] remember that if they find themselves in the situation of needing emergency contraception, Plan B does NOT prevent sexually transmitted infections,” says Dr. Ryniec. if this is your form of birth control, you'll want to stay on top of STD testing and use a form of protection, like condoms, to prevent against STDs.
Does Plan B get less effective over time?
No, says Dr. Ryniec — what matters is that you’re using it properly and before ovulation, but the effectiveness will not wane with subsequent use.
So no, Plan B doesn’t make you infertile.
Contrary to what you may see online, this is merely a myth. Using Plan B will not affect your fertility down the line. With that being said, it also doesn’t prevent STDs, so keeping that in mind and getting tested after unprotected sex is important.
Plan B is also not meant to be used each cycle, so if you find yourself taking it multiple times, you may want to consider switching to another form of contraception. As always, your doctor can address any questions you have.
Zara Hanawalt is a freelance journalist and mom of twins. She's written for outlets like Parents, MarieClaire, Elle, Cosmopolitan, Motherly, and many others. In her (admittedly limited!) free time, she enjoys cooking, reading, trying new restaurants, and traveling with her family.