Plan B One-Step, also known as the morning-after pill, is an oral medication that can prevent pregnancy when people have sex without contraception. Plan B does not end an already established pregnancy and does not protect against sexually transmitted infections (STIs) or diseases (STDs).

This article looks at Plan B One-Step, including effectiveness, potential side effects, and more.

Plan B One-Step (levonorgestrel) is an over-the-counter (OTC) emergency contraceptive approved by the Food and Drug Administration (FDA). For best results, a person should take it as soon as possible after having sex without using a condom or another form of barrier birth control or if contraception has failed.

How it works

According to the FDA, Plan B can work in two ways:

  • stopping the ovary from releasing an egg
  • preventing a fertilized egg from implanting in the uterus

Because Plan B stops the ovaries from releasing an egg, the sperm has nothing to fertilize, and pregnancy will not occur. If sperm fertilizes an egg, Plan B One-Step prevents the fertilized implanting in the uterus, making pregnancy impossible.

However, if a fertilized egg does implant in the uterus, the medication becomes ineffective. Anyone who thinks they might be pregnant may consider speaking with their doctor.

Plan B One-Step is most effective when taken as soon as possible within the first 72 hours after having sex without using barrier contraception or contraception failure.

Plan B may be less effective in people near ovulation or with a higher body mass index (BMI).

Plan B is an oral tablet. A person should follow all instructions on the product and talk to a healthcare professional if they have any questions.

Plan B One-Step is available OTC at most major pharmacies.

A person can also order online or schedule a pick-up at their local pharmacy.

Individuals do not need a prescription to get Plan B One-Step.

Plan B One-Step can cause side effects for some people. According to the FDA, some reported side effects include:

The most common side effect of Plan B One-Step is heavier menstrual bleeding. Otherwise, the FDA generally regards the medication as safe. In addition, People who are breastfeeding, or chestfeeding, can use the medication without adverse effects.

A person considering taking Plan B should talk with their doctor if they take other medications. The following medications reduce the effectiveness of Plan B:

The following are some frequently asked questions about Plan B One-Step.

How long do I have to take Plan B?

Plan B is a single-dose tablet. A person can take the tablet for up to 72 hours after unprotected sex, but sooner is better. Ideally, a person would take Plan B as soon as possible after having sex without using barrier contraception or having concerns that their contraception failed.

How much does Plan B cost?

Prices can vary for Plan B. A person can purchase Plan B One-Step for around $50 online. However, it may be best to buy the medication at a local pharmacy due to its time-limited effectiveness.

Does health insurance cover plan B?

Plan B One-Step is an OTC medication. This means that most insurance companies will not cover the costs. A person may be able to use their HSA or other medical savings to purchase the medication.

Plan B One-Step can provide the most effective birth control when taken within 12 hours. However, a person should not use the medication as their primary form of birth control.

An individual has several birth control options. Reversible birth control options include:

In some cases, a person may want a more permanent solution. A person with female reproductive organs can have a tubal ligation, in which a doctor will remove or block the fallopian tubes. A person with male reproductive organs can have a vasectomy, in which a doctor will block or remove the tubes that transport sperm. Though often referred to as permanent procedures, in most cases, doctors can reverse them.

A person may use a different form of emergency contraceptive if they prefer. Some generic versions are effective as Plan B, including:

Individuals may also consider Ella (ulipristal acetate), which can be effective up to 5 days after sex but requires a prescription.

Plan B One-Step is a single-dose emergency contraceptive. A person should not use it in place of regular birth control methods. The medication is most effective when taken within the first 72 hours after a person has sex without contraception or if there is a risk the contraception failed.

Plan B does not protect against STIs or other conditions and will not end an already established pregnancy.