Botulinum Toxin A for Hair Loss Treatment: A Systematic Review of Efficacy, Safety, and Future Directions

Background: Hair loss is a common condition with significant im-pact globally, yet its treatment efficacy and safety remain debated. Botulinum toxin A (BoNT-A) has emerged as a potential therapeutic option, but a comprehensive review on this topic is lacking.Objective: This review critically evaluates the current evidence on BoNT-A for hair loss treatment, highlighting the gaps in previ-ous reviews and providing a comprehensive analysis of its efficacy, safety, and future prospects.Methods: A systematic search of electronic databases identified rel-evant studies published up to September 2022 .Results: Prior reviews primarily focused on androgenetic alope-cia and lacked the evaluation of other alopecia types and under-lying mechanisms. Our review addresses this gap, incorporating a broader spectrum of hair loss conditions. Mechanisms of BoNT-A in hair growth modulation, potential side effects, and future research directions are discussed.Conclusion: This review adds to the existing body of knowledge by providing a comprehensive evaluation of BoNT-A in hair loss treat-ment. The findings will serve as a foundation for further research and guide clinicians in making informed decisions, ultimately im-proving the outcomes and quality of life for individuals suffering from hair loss.(c) 2023 The Authors. Published by Elsevier Ltd on behalf of British Association of Plastic, Reconstructive and Aesthetic Surgeons. This is an open access article under the CC BY license ( http://creativecommons.org/licenses/by/4.0/ )