Plan B and Plan B One-Step are brand name products containing the synthetic hormone levonorgestrel. They are used for emergency contraception during the 72-hour period following unprotected sexual intercourse. This drug can be purchased without a prescription by women 17 and over. Younger women must have a prescription to obtain Plan B. Taking the product immediately after intercourse affords the best protection from pregnancy.
Intended Effects
This drug is taken in an attempt to prevent pregnancy when semen has been released into the vagina. According to the FDA, the product often stops the release of an egg from one of the ovaries. If the egg has already been released, it may prevent the sperm from penetrating the egg. If the egg has already been fertilized, the drug may make the uterus lining inhospitable for implantation, meaning the fertilized egg cannot attach to the womb and grow.
Unintended Reproductive Effects
Like all medications, levonorgestrel has side effects. Women who take this product may encounter reproductive side effects, including breast tenderness and a late, light or missed period. Some women report having a heavy period after taking Plan B.
Other Unintended Effects
This product can cause gastrointestinal side effects. Events commonly reported include nausea, vomiting, diarrhea and pain in the abdominal area. Some patients become dizzy or overly tired. Drugs.com reports that headache is another frequent side effect of this product. A severe allergic reaction may occur with manifestations, including swollen lips, tongue, face and throat. This swelling can lead to difficulty breathing. Tightness in the chest, rash, itching and hives may also occur as part of the allergic response.
