Growing Hair with Botox
Mean hair counts rose and mean hair loss slowed after injections of botulinum toxin A.
Botulinum toxin A (BTX A) has been used for the treatment of wrinkles, hyperhidrosis, and headaches. Now, here comes an open-label pilot study from Canada of BTX A to treat androgenic alopecia. The study was supported by an educational grant from the manufacturer, and the authors hold intellectual property rights to the treatment process.
Fifty males with Norwood/Hamilton alopecia classes II to IV had injections to the scalp muscles (divided equally to the frontalis, temporalis, periauricular, and occipitalis) of a total of 150 units of BTX A, followed by a second session 24 weeks later. Assessment included change in hair counts in a 2-cm scalp area, changes in hair loss counts collected by lint roller from the subject’s pillow, and patient responses to a questionnaire. The 60-week study period consisted of a 12-week baseline lead-in period and two 24-week treatment periods following each BTX A treatment session.
In the 40 patients who completed the study, mean hair counts increased 18% from baseline to 48 weeks after the initial injection, a statistically significant change. Hair loss was also significantly reduced, by a mean of 39%. The reduction in hair loss and increase in hair counts were not correlated. The treatment response rate was 75%. The subjects noted statistically significant increased hair growth. No adverse events were noted.
Comment: The proposed mechanism for hair growth in androgenic alopecia after botulinum toxin A treatment is that paralysis of the scalp muscles enhances blood flow to the scalp by reducing the tension on the scalp skin. Because the conversion to dihydrotestosterone (DHT) is enhanced in a low-oxygen environment, oxygenated blood reduces this conversion and increases conversion to estradiol. This might be the same mechanism by which minoxidil affects androgenic alopecia. The 18% increase in hair count is similar to that achieved with finasteride. How injecting BTX A into scalp muscles could be protected as intellectual property is difficult to see.
George J. Hruza, MD
Published in Journal Watch Dermatology November 10, 2011
Freund BJ and Schwartz M. Treatment of male pattern baldness with botulinum toxin: A pilot study. Plast Reconstr Surg 2010 Nov; 126:246e.