Acne treatment using finasteride

The role of hormones in the development and proliferation of acne must not be ignored. Hormones are responsible for the maturation of the oil glands in our skin. Most of the androgens such as dihydrotestosterone (DHT) and testosterone, adrenal precursor dehydroepiandrosterone sulfate and estrogens are produced by the sex glands. Disorders of androgen excess production are associated with increased sebum production which ultimately makes the skin prone acne formation. Thus, to counter this condition, hormonal therapy that includes the use of anti androgens is recommended.

The role of Androgens

Androgens are part of the biology of gender by stimulating and controlling the development and maintenance of masculine characteristics. High level of serum androgen is associated with the development severe types of acne. Many biological processes are involved in the pathogenesis of acne and androgens play a key causal role in stimulating sebum production. However, there is still no general consensus among endocrinologists on whether serum androgen, locally produced androgens or a combination of both are responsible for acne formation.

Anti androgens in Hormonal Therapy for Women

Hormonal acne therapy aims to inhibit androgen production from the ovary or the adrenal glands through the use of anti-androgens, androgen-receptor blockers, and other agents. Anti-androgens impede the effects of androgens on the sebaceous glands, while androgen receptor blockers like cyprotene acetate, spironolactone, flutamide, and finesteride are used for severe acne with high levels of serum androgens. Hormonal therapy is ideal for women with the following characteristics:

Proven ovarian or adrenal hyperandrogenism
Hirsutism
Excessive sebum secretion
Acne beginning in adulthood, worsening before periods
Severe acne that’s resistant to other forms of treatment

Finasteride

DHT (dihydrotestosterone) is the effector androgen that mediates the production of sebum, and is about 5-10 times more potent than testosterone in its reaction with the functional androgen receptor, which in turn leads to acne production. DHT is produced from testosterone within peripheral tissues such as the skin, which is caused by the action of 5-alpha reductase enzymes. The facial area is often more prone to acne than other parts of the body since these enzymes exhibit more activity in facial sebaceous glands.

5-alpha reductase has two isozymes. The Type 1 isozyme is active in the sebaceous glands, while the Type 2 isozyme is most active in the prostate gland in men. Enhanced activity of the 5-alpha reductase 2 enzyme leads to the development of androsterone, and ultimately to severe acne formation, in adult women. Finasteride inhibits this enzyme specifically, and is sometimes specified for hypoandrogenic women in Europe. This practice has not been approved for North America as of this writing.

Finasteride’s efficacy in hyperandrogenic acne treatment is comparable to other well-known anti-androgen treatments, with miniscule daily dosages (5mg) effectively reduces acne. In patients who respond well to finasteride treatment, acne may be completely cured within three months.

Finasteride Compared to other Anti Androgens

While finasteride has been found to reduce acne lesions, total reduction is limited to only about 36%, which is inferior to the performance of the anti-androgen flutamide. Daily flutamide doses of only 250mg have been found to reduce acne by 60%, showing an efficacy similar to cyproterone acetate. This may be owing to the fact that finasteride inhibits the 5-alpha reductase’s Type 2 enzyme, while acne development is associated mainly with the Type 1 enzyme.

Associated Side Effects

Finasteride still sees wide use in androgenic acne treatment despite its lower effectiveness, owing to a much lower risk of side effects when compared with flutamide and cyproterone acetate. A daily dosage of 5mg shows no side effects at all, and finasteride does not interfere with menstruation. It also does not affect blood glucose levels or liver enzymes of women patients.

However, being an anti-androgen, finasteride use should be stopped by women who wish to get pregnant, as significant developmental defects in the embryo may arise. Finasteride is often prescribed along with oral contraceptives for women of childbearing age for this purpose.