Plan B

• Plan B is an emergency contraceptive pill primarily used to prevent pregnancy after unprotected sex.
• It works by delaying or preventing ovulation, not by causing an abortion.
• Effectiveness is highest when taken as soon as possible, ideally within 72 hours, but up to 120 hours after unprotected intercourse.
• Common side effects include nausea, fatigue, and changes in menstrual bleeding, which are typically mild and temporary.
• Plan B does not protect against sexually transmitted infections (STIs) and is not intended for routine birth control.

What is Plan B Emergency Contraception?

Plan B emergency contraception is an oral medication primarily containing levonorgestrel, a synthetic progestin hormone. It is specifically formulated to be used after unprotected sexual intercourse or when a regular birth control method has failed. The primary goal of Plan B is to prevent pregnancy, not to terminate an existing one. It is available over-the-counter without a prescription, making it an accessible option for urgent situations.

According to the Centers for Disease Control and Prevention (CDC), emergency contraception methods like Plan B can significantly reduce the risk of pregnancy when used correctly and promptly. It is distinct from regular birth control pills, as it contains a higher dose of hormones intended for single-use emergency situations rather than daily prevention.

How Plan B Works and Its Effectiveness Timeline

The mechanism of action for the Plan B pill primarily involves delaying or preventing ovulation. If ovulation has not yet occurred, the high dose of levonorgestrel can prevent the release of an egg from the ovary. Without an egg to fertilize, pregnancy cannot occur. It may also thicken cervical mucus, making it harder for sperm to reach an egg, and thin the uterine lining, though these effects are considered secondary to its primary action on ovulation. It is crucial to understand that Plan B does not work if a person is already pregnant, nor does it cause an abortion. It works by preventing fertilization or implantation, not by interrupting an established pregnancy.

The Plan B effectiveness timeline is highly dependent on how quickly the pill is taken after unprotected sex. Its efficacy decreases with time.

For optimal results, Plan B should be taken as soon as possible, ideally within 72 hours (three days) of unprotected intercourse. While some effectiveness may persist up to 120 hours (five days), it is significantly reduced. It is important to note that Plan B is not 100% effective and some pregnancies may still occur even with proper use.

Potential Side Effects and Risks of Plan B

While generally safe, Plan B side effects and risks can occur. Most side effects are mild and temporary, resolving within a day or two. Common side effects include:

• Nausea or vomiting
• Dizziness
• Fatigue
• Headache
• Breast tenderness
• Abdominal pain or cramps
• Changes in menstrual bleeding (e.g., earlier or later period, heavier or lighter flow, spotting)

If vomiting occurs within two hours of taking Plan B, it is recommended to contact a healthcare provider as another dose might be needed. While rare, more serious risks are not typically associated with Plan B itself but rather with underlying health conditions or interactions with other medications. Plan B does not protect against sexually transmitted infections (STIs), so barrier methods like condoms are still essential for STI prevention. It is also not recommended for routine use as a primary birth control method due to its higher hormone dose and potential for more frequent side effects compared to regular contraception. Individuals with concerns about side effects or who experience severe or persistent symptoms should consult a healthcare professional.