Androgenetic alopecia (AGA) is the most frequent cause of hair loss in men and women. According to epidemiological studies, 80% of Caucasian men and 40-50% of women will develop AGA over the course of their lifetime.1 AGA is characterized by a decrease in hair density in androgenetic areas of the scalp due to a progressive miniaturization of the hair follicle. The etiopathogenesis is multifactorial and complex.2

Androgens play an important role. Their influence is especially relevant in men, and still controversial in women.3,4 Hair follicles in persons with androgenetic alopecia (AGA) are genetically susceptible to androgens. The activity of 5-alpha-reductase enzyme converts free testosterone into 5-α-dihydrotestosterone (5-α-DHT). 5-α-DHT binds to the androgen receptor in the dermal papilla of the hair follicle and activates the genes responsible for the gradual hair loss. After several hair cycles, the duration of anagen phase shortens and matrix size decreases, resulting in clinically evident miniaturized hairs.4 Peripheral antiandrogens, like the inhibitors of 5-alpha-reductase, have been proven to be effective in stopping this mechanism and also to revert hair thinning. Oral finasteride, which inhibits type II enzyme, is an FDA approved drug to treat AGA. Oral dutasteride inhibits both type I and II enzymes, and its use in AGA is considered off-label. The systemic use of both drugs has been attributed to side effects including sexual impotence, ejaculation disorders, and decrease of libido. Although clinical trials have not demonstrated a clear correlation between the use of these drugs and those side effects,5 they represent a primary concern for patients considering treatment.

In order to limit systemic absorption of 5-alpha-reductase inhibitors, their use as mesotherapy preparations has increased over the last several years. Mesotherapy technique involves microinjection of substances into the dermis or subcutaneous tissue for the treatment of various dermatological conditions, such as alopecia, cellulite, and wrinkles.6,7 Dutasteride-containing preparations might be an option to treat AGA in