Abstract
AIM: Hydrogels are three-dimensional, water-rich polymer networks that enhance drug delivery, hydration, and tolerability in topical acne therapy. This systematic review and meta-analysis evaluated the efficacy and safety of hydrogel-based formulations for acne treatment. METHODS: Systematic search of PubMed, Embase, Scopus, and Cochrane Library (inception - September 2025) was performed following PRISMA guidelines. Eligible clinical trials assessed hydrogel-based therapies for acne reporting quantitative lesion outcomes. Random-effects meta-analysis was conducted using standardized mean difference (SMD) as the effect estimate. Risk of bias (RoB 2, ROBINS-I), heterogeneity (I(2)), and publication bias (funnel plot, Egger's test) were assessed. (PROSPERO: CRD420251140597). RESULTS: Thirteen studies (n = 3,654) met inclusion criteria, with seven (n = 2,986) included in the meta-analysis. Hydrogel-based formulations demonstrated favorable outcomes over comparators. Eight studies reported significant improvements in acne severity or lesion reduction (p < 0.05), while five showed non-significant but positive trends. Pooled meta-analysis confirmed significant benefit for hydrogels (SMD = -0.47, 95% CI - 0.78 to -0.16; p = 0.003). Despite high heterogeneity among meta-analyzed studies (I(2) = 86%), all showed consistent direction of effect favoring hydrogels. No serious events reported. CONCLUSION: Topical hydrogels effectively reduce acne lesions with excellent safety and tolerability. Larger, well-designed RCTs are warranted to confirm long-term outcomes.