Evaluating the efficacy and safety of combined microneedling therapy versus topical Minoxidil in androgenetic alopecia: a systematic review and meta-analysis

Abstract

This study evaluates the efficacy and safety of the combined microneedling (CMNT) with minoxidil versus minoxidil monotherapy for the treatment of androgenetic alopecia (AGA), with a focus on the impact of microneedling parameters on treatment outcomes. We conducted a systematic review and meta-analysis (PROSPERO: CRD42024594487) of randomized controlled trials (RCTs) comparing CMNT versus minoxidil alone for AGA, following PRISMA guidelines. A comprehensive search across six databases was performed up to September 8, 2024. We identified 12 RCTs involving 631 AGA patients, with a total of 11 RCTs included in the meta-analyses. CMNT significantly improved hair count compared to minoxidil monotherapy (SMD 1.32, 95% CI 0.73-1.92, p < 0.01), with substantial heterogeneity (I² = 88%, p < 0.01). Subgroup analyses indicated no significant effect of microneedling (MN) depth (≤ 1 mm vs. >1 mm), duration (≤ 12 weeks vs. >12 weeks), or technique(device) (electrodynamic vs. rolling) on hair count outcomes. Additionally, A meta-analysis of six RCTs demonstrated a significant improvement in hair diameter with CMNT (SMD 0.34, 95% CI 0.11-0.58; p < 0.01), with no observed heterogeneity (I² = 0%). Investigators and patient's self-assessment scores were also improved. Adverse events were more frequent with CMNT (74 vs. 59 events), however they were generally considered mild or self-limiting. CMNT significantly enhances hair count and diameter in AGA patients with mild adverse events. MN parameters including depth, duration, and technique variations did not significantly affect hair count outcome, suggesting microneedling as a promising adjunctive AGA treatment.

Keywords: Androgenetic alopecia; Depth; Diameter; Electrodynamic microneedling; Hair count; Hair diameter; Microneedling; Rolling microneedling.

Fig. 1

PRISMA flow diagram illustrating the study selection process for the systematic review and meta-analysis

Fig. 2

Traffic light plot summarizing the risk of bias assessment for the included studies

Fig. 3

Weighted bar plots illustrating the distribution of risk-of-bias judgments within each bias domain, categorizing them into low, some concern, or high risk

Fig. 4

Forest plot showing the overall standardized mean difference (SMD) of hair count between the combined microneedling and minoxidil group versus the minoxidil monotherapy group

Fig. 5

Forest plot of subgroup analysis demonstrating the effect of microneedling depth (> 1 mm vs. ≤1 mm) combined with minoxidil versus minoxidil monotherapy on hair count

Fig. 6

Forest plot of subgroup analysis illustrating the effect of microneedling therapy duration (> 12 weeks vs. ≤12 weeks) combined with minoxidil versus minoxidil monotherapy on hair count

Fig. 7

Forest plot of subgroup analysis examining the impact of microneedling technique (device) (electrodynamic vs. rolling) combined with minoxidil versus minoxidil monotherapy on hair count

Fig. 8

Forest plot showing the overall standardized mean difference (SMD) of hair diameter between the combined microneedling and minoxidil group and the minoxidil monotherapy group

Fig. 9

Forest plot of odds ratios comparing investigator’s assessment categories (improved, no change, and worsened) between the combined microneedling and minoxidil group and the minoxidil monotherapy group

Fig. 10

Forest plot of odds ratios comparing patient’s self-assessment score categories (improved, no change, and worsened) between the combined microneedling and minoxidil group and the minoxidil monotherapy group

Fig. 11

Forest plot of relative risk of scalp itching in the combined microneedling therapy compared to minoxidil monotherapy group

Fig. 12

Forest plot of relative risk (RR) of hypertrichosis in the combined microneedling therapy compared to minoxidil monotherapy group

Fig. 13

Funnel plot assessing potential publication bias for the hair count outcome across the included studies