Effect of Microneedle on Hair Regrowth in Patients with Androgenetic Alopecia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Abstract

Objective Our objective was to assess the effectiveness and safety of microneedle by comparing microneedle plus 5% topical minoxidil treatment and microneedle alone to 5% topical minoxidil.Methods We searched databases such as Embase, PubMed, Cochrane library, VIP Database for Chinese Technical Periodicals, Wanfang, and China National Knowledge Infrastructure in relation to literature. The control group received 5% topical minoxidil solution, whereas the treatment group received either microneedle coupled with minoxidil or microneedle alone. The increase in hair count and hair diameter was the main evaluation criterion for assessing hair regrowth. Data were pooled with Stata 15 software.Results Eight studies with 472 participants were included. Compared with 5% topical minoxidil therapy, microneedle plus minoxidil treatment showed a significant increase in hair count (standard mean difference [SMD] :15.82, 95% confidence interval [CI]: 12.34, 19.31, p < 0.05), but no increase in hair diameter (SMD: −0.21, 95% CI: −2.94, 2.52, p = 0.879 > 0.05). The results of subgroup analysis suggested that microneedle plus minoxidil treatment showed a significant increase in hair count whether the depth of microneedle was less than 1 mm (SMD:1.16, 95% CI: 0.86, 1.42, p < 0.05) or more than 1 mm (SMD:0.52, 95% CI: 0.23, 0.82, p < 0.05). In terms of treatment period subgroup, microneedle combined with minoxidil therapy significantly increased hair count and hair diameter than single 5% topical minoxidil, whether in 12-week period (SMD: 1.08, 95% CI: 0.76, 1.39, p < 0.05) or 21 to 24 weeks period (SMD: 0.64: 95%, CI: 0.35, 0.92, p < 0.05).Conclusion According to this study, the effect of microneedle treatment alone on androgenetic alopecia (AGA) may be limited. However, microneedle plus 5% topical minoxidil treatment had better hair regrowth in hair count and can be considered as an additional therapy option for AGA. Combined with subgroup analysis results, 12-week period and less than 1 mm depth of microneedle penetration were recommended.