Cyproterone Acetate for Acne and Hirsutism: Dosage and Usage Guidelines
Cyproterone acetate is recommended at a dose of 2mg combined with 35μg ethinylestradiol for treating moderate to severe acne related to androgen sensitivity and/or hirsutism in women of reproductive age. 1, 2
Mechanism of Action
- Cyproterone acetate works through dual mechanisms: competitive inhibition of androgen receptor binding and negative feedback on the hypothalamic-pituitary axis to suppress testosterone production 3
- This anti-androgenic effect makes it particularly effective for treating hyperandrogenic skin conditions like acne and hirsutism 2
Dosage and Administration
- For acne and hirsutism treatment, the standard formulation is 2mg cyproterone acetate combined with 35μg ethinylestradiol 1, 2
- This combination should be administered cyclically (21 days on, 7 days off) to ensure proper menstrual cycling 2
- For more severe cases of hirsutism, higher doses of cyproterone acetate (50-100mg daily) may be used for the first 10 days of the cycle, in addition to the combined formulation 4
- Treatment duration should be long-term, as therapeutic response in women with hirsutism requires sustained therapy 2
Efficacy
- Clinical studies show high efficacy rates: 94% success for acne and 85% for hirsutism 4
- Cyproterone acetate is more effective than spironolactone for treating hyperandrogenic skin conditions 5
- Visible improvement typically begins after 3-6 months of treatment, with maximum effects seen after 9-12 months 2
Clinical Applications
Acne
- Most effective for moderate to severe acne with an androgenic pattern (jawline, chin, neck) 2
- Particularly beneficial when acne is accompanied by seborrhea 1
- Can be considered when other treatments (topical agents, oral antibiotics) have failed 6
Hirsutism
- Effective for reducing excess hair growth in androgen-sensitive areas 4
- Should be considered as a hormonal treatment option for women with hirsutism 6
- May take 6-12 months for maximum effect on hair growth 2
Polycystic Ovary Syndrome (PCOS)
- Effectively treats PCO-related hyperandrogenic skin symptoms 1
- Provides additional benefits for menstrual irregularities common in PCOS 1
- Reduces risk of endometrial cancer in women with PCOS 1
Contraindications and Precautions
- Should not be used in patients with liver disease due to potential hepatotoxicity 3
- Contraindicated during pregnancy and lactation 6
- Caution advised when using in combination with estrogens in patients with history of thromboembolic disorders 3
- Should be avoided in patients with hereditary angioedema as it may worsen the condition 3
Monitoring and Side Effects
- Liver function tests should be monitored periodically due to potential hepatotoxicity 3
- Side effects are similar to those of estrogen-containing contraceptives 4
- Venous thromboembolism is a potential risk that should be considered in the risk-benefit assessment 1
- Long-term metabolic and cardiovascular effects require further investigation 1
Alternative Options
- Spironolactone (50-200mg daily) is an alternative anti-androgen that may be better tolerated for long-term use, though less effective 7, 5
- Combined oral contraceptives containing drospirenone may be considered as alternatives with milder anti-androgenic effects 6
- For acne specifically, topical treatments (retinoids, benzoyl peroxide) should be used concomitantly for optimal results 6
Cyproterone acetate combined with ethinylestradiol remains one of the most effective treatments for hyperandrogenic skin conditions, with high success rates for both acne and hirsutism when used appropriately and with proper monitoring.