摘要Background:Androgenetic alopecia(AGA)is a common hair loss disorder that significantly affects patient's quality of life.Botulinum toxin(BoNT)has emerged as a potential treatment;however,its effectiveness and underlying mechanisms remain unclear.This systematic review aimed to synthesize the existing evidence on BoNT for AGA,analyze its mechanisms,evaluate its efficacy,and explore its potential for precision therapy.Methods:A PubMed search was conducted for studies published between 2020 and 2025.A total of 25 studies,including 11 clinical trials and 7 reviews,were included.The studies were analyzed for BoNT mechanisms in AGA,treatment regimens,efficacy,outcomes,cost-effectiveness,and safety profiles.Results:Experimental evidence suggests that BoNT reduces transforming growth factor-β in dermal papilla cells,a key pathological pathway in AGA.Other hypothetical mechanisms,such as scalp muscle relaxation improving microcirculation or inhibiting androgen conversion require further validation.In clinical trials,most studies used 30-150 U of BoNT via intramuscular(six studies)or intradermal(three studies)injections,with 1-3 sessions and up to 6 months of follow-up.Early open-label trials reported response rates of 70％-79％,but recent high-quality randomized controlled trials(RCTs)showed no significant improvement in hair density compared to placebo.Combination therapy with finasteride or minoxidil enhanced treatment outcomes,though large-scale evidence is lacking.BoNT was less cost-effective than first-line therapies such as minoxidil,with session costs approximately 37 times higher.Intramuscular injection appeared more effective than intradermal injection,possibly due to scalp muscle relaxation and vascular decompression.BoNT generally had a mild safety profile.Conclusion:Currently,BoNT lacks robust evidence to replace traditional treatments for AGA.Future research should focus on establishing standardized dosing protocols,conducting large-scale,long-term RCTs,and inte-grating molecular biomarkers to improve understanding and optimize the clinical use of BoNT in AGA management.