Gallic acid is a naturally occurring polyphenol found in various plants, fruits, and teas. It has been studied for its antioxidant, anti-inflammatory, and antimicrobial properties. Regarding dermatitis, several preclinical studies (in vitro and animal models) have demonstrated that gallic acid can reduce skin inflammation and oxidative stress, both of which are key factors in the pathogenesis of dermatitis. For example, a 2016 study published in Phytotherapy Research showed that topical application of gallic acid attenuated symptoms of atopic dermatitis in mice by downregulating pro-inflammatory cytokines and reducing skin lesions. Additional studies have found that gallic acid inhibits the activation of NF-κB, a transcription factor involved in inflammatory responses, and scavenges free radicals that can damage skin cells.

However, clinical evidence in humans is very limited. Most available research consists of laboratory or animal studies rather than well-controlled human trials. There is little to no documentation of gallic acid’s use for dermatitis in traditional medicine systems. Thus, while there is a plausible scientific basis and promising early findings, the evidence is not robust, and more research—particularly human clinical trials—is needed to confirm its efficacy and safety for dermatitis management.