Potash Alum as a Natural Deodorant: Comprehensive Review of Formulation, Efficacy, and Safety

Abstract

Potash alum (potassium aluminum sulphate) has resurfaced as a promising natural deodorant in response to global demand for safer, eco-conscious, and effective personal care solutions. Unlike synthetic antiperspirants that block sweat glands, alum acts by modulating skin microflora and exerting gentle astringency, thus controlling odor without altering normal perspiration. This review critically evaluates the chemistry, antimicrobial mechanism, formulation strategies, clinical effectiveness, and regulatory considerations of potash alum. Evidence from recent in vitro, ex vivo, and consumer trials consistently supports its role as a safe, non-irritant deodorizing agent. Comparisons with synthetic aluminum salts highlight its lower irritation potential and compatibility with “clean beauty” philosophies. Emerging research also explores alum’s integration into modern delivery systems such as hydrogels, nanocarriers, and hybrid herbal formulations, expanding its relevance in cosmetic innovation. This paper identifies key research gaps, especially regarding long-term dermatological safety and sustainable sourcing, and proposes future directions for advancing alum-based deodorants.