Microneedling Versus Chemical Peels for Atrophic Acne Scars: A Systematic Review and Meta-Analysis

Atrophic acne scarring is a common complication of acne vulgaris and is associated with a significant psychosocial burden. Among the various treatment options available, microneedling and chemical peels are widely used due to their accessibility and favourable safety profiles. However, uncertainty remains regarding their comparative effectiveness and safety. Hence, the aim of this review is to compare the effectiveness of microneedling versus chemical peels in improving the severity of atrophic acne scars and to evaluate patient satisfaction and adverse events associated with these interventions. Randomized and non-randomized clinical trials were included. Outcomes were categorized as clinically significant improvement (≥50% improvement), any improvement (≥1 grade improvement), and continuous measures of scar severity. Dichotomous outcomes were pooled using risk ratios (RR), while continuous outcomes were analyzed using standardized mean differences (SMD). Outcomes that could not be quantitatively synthesized were analyzed narratively. A total of 11 studies comprising 713 participants were included. Meta-analysis of clinically significant improvement (five studies; n = 215) showed no significant difference between microneedling and chemical peels (RR = 0.97; 95% CI: 0.82-1.15; p = 0.74; I² = 0%). However, microneedling was associated with a significantly higher likelihood of achieving any improvement (four studies; n = 264; RR = 1.79; 95% CI: 1.37-2.34; p < 0.0001; I² = 0%). Analysis of continuous outcomes (four studies; n = 211) showed no significant difference, with a trend favouring chemical peels (SMD = -0.27; 95% CI: -0.91 to 0.38; p = 0.41; I² = 80%). Findings on patient satisfaction were inconsistent, while adverse events varied between interventions, with microneedling associated with greater procedural pain and chemical peels associated with burning sensations and exfoliation. Microneedling and chemical peels appear to be broadly comparable in the treatment of atrophic acne scars, with no clear evidence of superiority. While microneedling may be more effective in achieving minimal improvement, and chemical peels may show advantages in certain continuous measures, these differences are not consistent across outcomes. Treatment decisions should therefore be individualized. Further high-quality studies with standardized outcome measures are needed to strengthen the evidence base.