What Are the Risks of Taking Plan B Too Often?

Plan B is an emergency contraception pill that can prevent pregnancy after unprotected sex. It can also cause menstruation issues if used too frequently.

It is also known by other brand names such as Take Action, My Way, Option 2, Preventeza, AfterPill, My Choice, Aftera and EContra.

The dosage for Plan B used to be two 0.75-milligram pills taken 12 hours apart, but this system has been largely replaced by Plan B One-Step, which is just one 1.5-mg pill.

The active ingredient in Plan B pills is levonorgestrel, a progestin, a hormone commonly found in regular birth control pills.

However, it is a higher dosage than normal progestin pills.

"Plan B acts primarily by stopping the release of an egg from the ovary [ovulation]," said Monica Grover, D.O., an OB-GYN and the chief medical officer at VSPOT, a women's sexual health practice based in New York City. It can also stop fertilization and implantation, she added.

The documented side effects of Plan B can include:

• Nausea
• Vomiting
• Menstrual irregularities
• Dizziness
• Diarrhea
• Breast tenderness
• Headache
• Tiredness
• Abdominal cramps

It is important to remember that while emergency contraception is not dangerous and taking it a lot does not make it less effective, frequent exposure to its hormones can cause a few issues.

"Taking Plan B repeatedly will expose you to higher hormone levels than standard contraceptive methods and is likely to cause more side effects, such as menstrual changes, headache or abdominal pain," Grover explained.

Some side effects

The purpose of Plan B means one of the biggest problems it can cause is with your period, as it can create irregular bleeding that can be heavier or lighter than usual, said Cristin Hackel, R.N.C., M.S.N., a nurse practitioner in Bethesda, Maryland, and medical provider at Nurx, an online healthcare company.

"The more often you take it, the more irregular bleeding you may experience, which also makes it hard to know when your usual cycle will occur or when you may be ovulating," she added.

Period tracking, or menstrual mapping, is useful for reasons beyond fertility because it can help you to understand how your hormones affect your mood, sleep, energy levels and even your digestion.

The inability to track your period means it is possible to miss signs of illness and even pregnancy, which is why it is recommended to take a pregnancy test if your period is more than a week late after taking Plan B.

Grover explained that until your menstrual and ovulation cycles return to normal, you may have a more difficult time planning for an intended pregnancy.

Plan B has a 75 percent to 89 percent effectiveness rate at preventing pregnancy if taken within three days. Overall, when taken correctly, Plan B prevents 7 in 8 pregnancies.

The Food and Drug Administration approved unrestricted sales for Plan B in 2013. It can be sold over the counter in pharmacies in every state. If you are already pregnant, it will not affect that pregnancy. As it is for contraceptive and not abortive purposes, its availability to customers is not affected by the 2022 Supreme Court ruling that overturned Roe v. Wade.

The most common alternative emergency contraceptive pill is Ella. It has an 85 percent success rate if used within five days of unprotected sex. It is sometimes advised for people who weigh more than 165 pounds, but the evidence for weight guidelines is conflicting. However, Ella requires a prescription whereas Plan B does not.

It is for all of these reasons that Hackel recommended "if you find yourself needing Plan B often, please consider a more consistent method of birth control to use."

Emergency contraceptives to consider

From a financial perspective, it can be much cheaper to use regular birth control than Plan B or its alternatives. Many contraceptives have more than 99 percent efficacy when used according to instructions and they can last anywhere from up to 10 years or forever if you opt for a permanent option. Speak to a physician who can advise you on what is best for you based on your lifestyle and needs.

Contraception options include:

• Diaphragm or cap. 92 percent to 96 percent effective at preventing pregnancy when used correctly.
• The implant (Nexplanon). More than 99 percent effective and lasts for three years.
• Intrauterine system (IUS). 99 percent effective when inserted correctly.
• Intrauterine device (IUD or coil). 99 percent effective when inserted correctly. Lasts for five to 10 years.
• Contraceptive injection. Lasts for eight to 13 weeks depending on the brand.
• Combined pill. 99 percent effective. Taken for 21 days, then a seven-day break.
• Progestogen-only pill (three-hour or 12-hour). It can be more than 99 percent effective, but it is often taken incorrectly due to the time frame limit.
• Vaginal ring (NuvaRing). More than 99 percent effective if used correctly. Each ring lasts for one month.
• Contraceptive patch. Each patch lasts for one week, with a one-week break after three weeks. More than 99 percent effective when used properly.
• Vasectomy. Permanent method for males.
• Sterilization (tubal ligation). Permanent method for females.
• Condoms. 98 percent effective when used properly.

One of the biggest risks associated with Plan B is sexually transmitted infections (STIs).

"Plan B does not protect against sexually transmitted infections, and among contraceptives, only condoms lower the risk of STIs," Grover said.

Condoms can help protect against these common sexually transmitted conditions:

• Chlamydia
• Gonorrhea
• Syphilis
• HIV (human immunodeficiency virus)
• Hepatitis
• Trichomoniasis
• Herpes
• HPV (human papillomavirus)
• Mycoplasma genitalium (Mgen)
• Pelvic inflammatory disease (PID)

It is important to note that there are medications and supplements that can render Plan B less efficient. Always discuss existing medications with your doctor.

These are some common drugs that can affect Plan B:

• Barbiturates
• Bosentan
• Carbamazepine
• Felbamate
• Griseofulvin
• Oxcarbazepine
• Phenytoin
• Rifampin
• St. John's wort
• Topiramate
• Some HIV/AIDS medications

For all of these reasons, it is as essential to take control of your sexual health choices as any other element of your health. Long-term contraception options can help you avoid the stress, costs and side effects of using Plan B, as well as offer much better protection against unwanted pregnancy or even make trying to conceive more straightforward when the time comes.