Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Plan B (Levonorgestrel).
Decreased effectiveness: This medication may be less effective for women who weigh more than 165 pounds (75 kg) . Regardless of body weight, Plan B (Levonorgestrel) should be taken as soon after unprotected intercourse as possible to ensure the most reliable outcome. If you weigh more than 165 pounds, you may wish to contact your doctor or pharmacist for advice about emergency contraception.
Diabetes: Although few women have experienced loss of blood glucose control when taking progestin-only pills, women with diabetes should monitor their blood glucose carefully after taking Plan B (Levonorgestrel).
Liver problems: The safety of using Plan B (Levonorgestrel) has not been established for people with liver disease. If you have liver disease, discuss with your doctor whether any special monitoring is needed.
Migraine: After taking a dose of Plan B (Levonorgestrel), you may experience a severe headache or a migraine.
Sexually transmitted infections: This medication does not protect against sexually transmitted infections, including HIV or AIDS. For protection against these infections, latex condoms should be used.
Pregnancy: Plan B (Levonorgestrel) should not be used during pregnancy. It will not terminate a pregnancy that has already been established.
Breast-feeding: Small amounts of progestin pass into the breast milk of women taking progestin-only pills. No adverse effects have been found with taking Plan B (Levonorgestrel) while breast-feeding, either in the quality and quantity of milk or in the growth and development of the infant.