Danazol
Androgens
AndrogensPregnancy: contraindicated
Contraindicated: it can virilise a female fetus (clitoral enlargement, ambiguous genitalia); pregnancy is excluded before starting and barrier contraception is used.
A synthetic weak androgen that suppresses the pituitary-ovarian axis. Used for endometriosis and to prevent hereditary angioedema attacks; harmful in pregnancy.
Quick facts
- Group
- Androgens
- Target
- Androgen and other gonadal steroid receptors; it suppresses pituitary FSH and LH
- Used for
- Prevention of attacks
- Key effects
- Weight gain · Acne · Decreased breast size
- Monitor
- Pregnancy test before starting · Liver function
- ATC
- G03XA01
No doses: the clinician sets them by the current guideline.
Mechanism of action
Danazol is a synthetic derivative of ethisterone. It suppresses the pituitary-ovarian axis, lowering FSH and LH output, so the ovaries make less estrogen and endometrial tissue, including endometriotic implants, becomes inactive and atrophic. It binds androgen and other gonadal steroid receptors and has weak androgenic activity, which explains acne, hirsutism and voice change. It also prevents attacks of hereditary angioedema.
- Danazol suppresses the pituitary release of FSH and LH
- Ovarian estrogen production falls
- Endometrial tissue and implants become atrophic
- Weak androgen action causes acne, hair growth and voice change
Indications
- Endometriosis amenable to hormonal treatment Endometriosis →
- Prevention of attacks of hereditary angioedema in men and women
- Fibrocystic breast disease when other treatments fail Fibrocystic breast changes →
Adverse effects
Common
- Weight gain, fluid retention
- Acne, oily skin, mild hirsutism
- Decreased breast size
- Hot flushes, sweating, vaginal dryness
- Menstrual changes, irritability
Contraindications
- Pregnancy and breastfeeding
- Undiagnosed abnormal genital bleeding
- Markedly impaired liver, kidney or heart function
- Porphyria
- Androgen-dependent tumour
- Active or past thrombosis or thromboembolism; hypersensitivity
Key interactions
- Warfarin
- Prolonged prothrombin time; bleeding risk
- Carbamazepine
- Higher carbamazepine levels
- Ciclosporin and tacrolimus
- Higher levels and kidney toxicity
- Simvastatin, atorvastatin, lovastatin
- More risk of myopathy and rhabdomyolysis
- Insulin and other antidiabetics
- Insulin resistance; glucose control changes
What is monitored
- Pregnancy test before starting
- Liver function
- Lipids
- Headache, vision and signs of thrombosis
- Voice changes and other androgenic effects
Administration and safety
- Oral capsules
- A sensitive pregnancy test is done before starting
- A non-hormonal (barrier) contraceptive method is used during treatment
Pregnancy and breastfeeding
Contraindicated: it can virilise a female fetus (clitoral enlargement, ambiguous genitalia); pregnancy is excluded before starting and barrier contraception is used.
Nursing care
- Confirm a negative pregnancy test and teach barrier contraception
- Teach to report hoarseness or voice deepening early
- Teach the warning signs of clots, raised intracranial pressure (headache, vomiting, vision change) and liver problems
- Check for warfarin, statins or immunosuppressants
- Ask about breastfeeding
Pharmacokinetics
- Absorption
- Oral capsules
- Metabolism
- Slowly, in the liver; ethisterone is a main metabolite
Test yourself
Think of the answer, then tap the question to see it.
How does danazol treat endometriosis?
It suppresses pituitary FSH and LH, lowers ovarian estrogen and makes endometrial implants atrophic.
Which androgenic effect of danazol may be permanent?
Deepening or hoarseness of the voice, which may persist after stopping.
Why is a non-hormonal contraceptive used with danazol?
Danazol is teratogenic (virilises a female fetus), and hormonal contraceptives may not be reliable alongside it.
Which statin interaction is listed for danazol?
Simvastatin, atorvastatin and lovastatin: a higher risk of myopathy and rhabdomyolysis.
Connections
← Back to the class: Androgens
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - DANAZOL capsule (DailyMed (U.S. National Library of Medicine), 2026); Danazol: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2017); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.