Mesotherapy has recently become an advertised method for the treatment of different types of alopecia despite the lack of any data regarding its efficacy and possible side effects. The substances injected into the scalp include "cocktails" of natural plant extracts, homoeopathic agents, vitamins, vasodilators, and drugs that may stimulate hair growth, such as finasteride and minoxidil. We report two cases of patchy alopecia that developed after mesotherapy for the treatment of androgenetic alopecia. In the first patient, alopecia developed after injections of the heparinoid vasodilator mesoglycan; the 3-month follow-up examination revealed a small residual area of cicatricial alopecia. The second patient developed reversible alopecia after multiple scalp injections of homeopathic agents. These cases underline the possible risks of mesotherapy as a therapeutic technique for hair loss.