What's New in Therapy for Male Androgenetic Alopecia?

Abstract

Male androgenetic alopecia is a common condition and represents a major concern for patients who experience this condition. While there are different treatments to stop hair loss and improve hair density, the 5-alpha reductase inhibitors have demonstrated to be effective in improving androgenetic alopecia in men and can maintain a positive response for many years. Oral finasteride 1 mg is a US FDA-approved option, but dutasteride 0.5 mg has been proven to induce better responses, especially in the frontal area. Both have been shown to be safe in clinical trials but there is widespread concern about sexual adverse effects among patients. The use of topical finasteride has increased during the last few years as a useful option to avoid systemic therapy. The efficacy of topical finasteride 0.25% daily has been demonstrated in clinical trials, with a less marked decrease in serum dihydrotestosterone levels than with oral intake. Mesotherapy with dutasteride has also become more widespread recently, although evidence of its effectiveness is limited to retrospective studies in real clinical practice. The use of oral minoxidil in androgenetic alopecia has not been approved by the FDA, however several clinical studies have shown that it is an effective treatment option. The initial dose recommended to treat male hair loss is 2.5 mg daily, although the dose is frequently increased to 5 mg daily. The main adverse effect of oral minoxidil is hypertrichosis, followed by dizziness or lower limb edema, which are much less common. Platelet-rich plasma is a non-pharmacological option to treat male androgenetic alopecia, with some clinical trials demonstrating an improvement in hair count after several months. Among the published studies, the main limitation to compare its efficacy is the heterogeneity of the procedure. The most frequent regimens propose treatment every 4 weeks for 3 months initially to assess the individual response. Another treatment alternative is the use of light devices with wavelengths of between 630 and 660 nm, known as low-level laser therapy. These devices can be used at home every day for 15-30 min. Their efficacy has been shown in a limited number of clinical trials; however, there is a lack of evidence about the efficacy of these devices compared with other medical options or as a complementary therapy in hair loss. The pipeline of potential new treatments for male androgenetic alopecia is strong. Pyrilutamide and GT20029 are being studied as topical antagonists of the androgen receptor, while cetirizine is another topical option with some initial promising results. Furthermore, according to isolated studies with heterogeneous treatment schemes, the use of botulinum toxin in the scalp might improve androgenetic alopecia, and lastly, scalp threading might increase the total hair count as growth factors are released during implantation.