Anaphylaxis & anaphylactoid reaction. Loss of bone mineral density. Increased risk of osteoporotic fracture in younger women. Do not use as long-term birth control method (ie, >2 yr) unless other birth controls are considered inadequate. Patients w/ risk factors for osteoporosis eg, metabolic bone disease, chronic alcohol &/or tobacco use, anorexia nervosa, strong family history of osteoporosis or chronic use of drugs that can reduce bone mass eg, anticonvulsants or corticosteroids. Discontinue treatment if thrombosis, jaundice, acute or chronic disturbances of liver function develops. Risk of breast, cervical, ovarian & liver cancer. Possibility of ectopic pregnancy in women who became pregnant or those who complain of severe abdominal pain. Convulsions. Monitor patients w/ history of depression & do not re-administer if depression occurs. Altered menstrual bleeding patterns including amenorrhea, irregular or unpredictable bleeding or spotting, prolonged spotting or bleeding, & heavy bleeding. Wt gain. Monitor diabetic patients, patients w/ epilepsy, migraine, asthma & cardiac or renal dysfunction. Fluid retention. Do not use during pregnancy. Lactation. Adolescents.