Background

In many people, acne is caused by increases in the growth and activity of the sebaceous glands.  These changes in the sebaceous glands are often stimulated by increases in androgenic hormones, such as those mass-produced during puberty.  Androgen hormones are a class of hormones that that help establish and maintain male characteristics.  Both males and females produce androgenic hormones, although the levels in males are generally much higher.  In addition to growth of the sebaceous glands, androgens stimulate other masculinizing characteristics such increased muscle mass, aggression and body/facial hair growth.  Androgen inhibitors can decrease the effect of androgens and generally have a feminizing impact on the patient.  In addition to acne treatment, androgen inhibitors are used in males to treat enlarged prostate, androgen dependent cancer and male pattern baldness.  In females, androgen inhibitors are used to treat hirsutism (excessive body and facial hair growth) and other symptoms of androgen induced masculinization.  At high doses, androgen inhibitors have been used in male to female sex re-assignment and as part of a chemical castration program for predatory sex offenders.  Because of the feminizing side effects of treatment, androgen inhibitors are usually better suited for use in women then in men, although research indicates that low dose treatments can be effective with minimal side effects.

Spironolactone (Aldactone)

Spironolactone is a commonly prescribed anti-androgen that is generally well tolerated by patients suffering from acne.   Research indicates that spironolactone can be an effective treatment for acne in women. Spironolactone functions by binding to the androgen receptor, preventing it from being activated by the androgen hormone, dihydrotestoserone.  This process, called competitive antagonism, decreases the sensitivity of the patient’s body (including the sebaceous glands) to androgen hormones. This can lead to a decrease in sebum production, sebaceous gland proliferation and as a result, improve acne symptoms.

Cyproterone (Androcur)

Like spironolactone, cyproterone is an anti-androgen treatment that prevents androgen hormones from binding to androgen receptors.  It is available by itself and as part of a combined oral contraceptive pill (Dianette/Diane 35) which also contains an estrogen hormone, ethinylestradiol.   Cyproterone has a relatively similar efficacy profile as spironolactone and can be quite effective for the treatment of acne in women. Cyproterone has a wider range of potential side-effects than spironolactone, owing to a broader spectrum of activity on the hormonal system.

Bicalutamide and Flutamide

Bicalutamide and flutamide are androgen receptor antagonists. They work by preventing androgens (eg. testosterone) from activating the androgen receptor.

Finasteride and Dutasteride

Finasteride and Dutasteride inhibit the activity of an enzyme that converts testosterone into dihydrotestosterone (DHT). DHT is a stronger androgen than normal testosterone. This enzyme is called 5-Alpha Reductase.

Related Articles from The Science of Acne

What is Acne Vulgaris?
What Causes Acne?
Prescription Medications and Acne Vulgaris
Naturopathic Medicine and Acne Vulgaris
Light and Laser Therapies and Acne Vulgaris
Over the Counter Medications (OTC) and Acne Vulgaris

References and Sources

Books

PDR Staff Writers. 2011. 2011 Physicians’ Desk Reference (PDR)
Habif. 2009. Clinical Dermatology
Goodheart. 2006. Acne For Dummies

Online Resources

Androgen Hormones @ Wikipedia
Acne Vulgaris @ Wikipedia
Acne Vulgaris @ eMedicine
Acne Treatment Reviews @ WebMD
Acne Treatment Reviews @ Acne.org

Scientific Research Articles

Zouboulis, et al. 2010. Hormonal antiandrogens in acne treatment.
Katsambas, et al. 2010. Hormonal therapy for acne: why not as first line therapy? facts and controversies.
Gruber, et al. 1998. Topical cyproterone acetate treatment in women with acne: a placebo-controlled trial.
Moghetti, et al. 2006. Treatment of hirsutism and acne in hyperandrogenism.
Thiboutot, et al. 2001. Endocrinological evaluation and hormonal therapy for women with difficult acne.
Thiboutot, et al. 2003. Update and future of hormonal therapy in acne.
Zouboulis, et al. 2003. Update and future of systemic acne treatment.
Leyden, et al. 2009. Clinical considerations in the treatment of acne vulgaris and other inflammatory skin disorders: a status report.
Williams, et al. 2011. Acne vulgaris.
Davis, et al. 2010. A review of acne in ethnic skin: Pathogenesis, clinical manifestations, and management strategies.
Sathish, et al. 2011. Acne and Its Treatment Options – A Review.
Ingram, et al. 2009. Management of acne vulgaris: an evidence-based update.
Schroeder, et al. 2012. Medications used for Acne vulgaris: Practice trends and the use of topical combination products.
Barratt, et al. 2008. Outcome measures in acne vulgaris: systematic review.
Patel, et al. 2010.The development of antimicrobial resistance due to the antibiotic treatment of acne vulgaris: a review. Strauss, et al. 2007.  Guidelines of care for acne vulgaris management.