It is very important that your doctor check your progress at regular visits to make sure that danazol does not cause unwanted effects. Blood tests may be needed to check for unwanted effects.

Using danazol while you are pregnant can harm your unborn baby. If you are a woman who can bear children, your doctor may give you a pregnancy test before you start using danazol to make sure you are not pregnant. Your birth control pills may not work as well while you are using danazol. You must use an effective form of birth control (e.g., a condom, a diaphragm, spermicide) to keep from getting pregnant. If you think you have become pregnant while using the medicine, tell your doctor right away.

Using danazol may cause irregular monthly periods or absence of menstrual period. If your regular monthly period does not begin within 60 to 90 days after you stop taking danazol, check with your doctor right away.

Check with your doctor right away if you are a female and have a larger clitoris (sexual organ), deepening of your voice, or unusual hair growth after taking danazol. Your doctor may advise you to stop taking the medicine so these side effects do not get worse.

Stop using danazol and check with your doctor if you have the following symptoms while taking danazol: blurred vision; change in the ability to see colors, especially blue or yellow; headache; nausea; or vomiting.

For patients with diabetes:
danazol may affect blood sugar levels. If you notice a change in the results of your blood or urine sugar tests, check with your doctor.

Before you have any medical tests, tell the medical doctor in charge that you are taking danazol. The results of some tests may be affected by danazol.

Danazol may rarely cause your skin to be more sensitive to sunlight than it is normally. Exposure to sunlight, even for brief periods of time, may cause a skin rash, itching, redness, or other discoloration of the skin, or a severe sunburn. Check with your doctor if this occurs.

Do not take other medicines unless they have been discussed with your doctor.

Androgen like effects include weight gain, acne and seborrhea. Mild hirsutism, edema, hair loss, voice change, which may take the form of hoarseness, sore throat or of instability or deepening of pitch, may occur and may persist after cessation of therapy. Hypertrophy of the clitoris is rare.

Other possible endocrine effects include menstrual disturbances in the form of spotting, alteration of the timing of the cycle and amenorrhea. Although cyclical bleeding and ovulation usually return within 60-90 days after discontinuation of therapy with Danazol, persistent amenorrhea has occasionally been reported.

Flushing, sweating, vaginal dryness and irritation and reduction in breast size, may reflect lowering of estrogen. Nervousness and emotional lability have been reported. In the male a modest reduction in spermatogenesis may be evident during treatment. Abnormalities in semen volume, viscosity, sperm count, and motility may occur in patients receiving long-term therapy.

Hepatic dysfunction, as evidenced by reversible elevated serum enzymes and/or jaundice, has been reported in patients receiving a daily dosage of Danazol of 400 mg or more. It is recommended that patients receiving Danazol be monitored for hepatic dysfunction by laboratory tests and clinical observation. Serious hepatic toxicity including cholestatic jaundice, peliosis hepatis, and hepatic adenoma have been reported.