Strategic Developments for Pre-clinical Safety/Efficacy Studies of Hair Care Products

Hair plays a substantial role in human biology and social interactions. In addition to providing a physical barrier, protecting the head from sunburn and temperature extremes, hair also reflects an individual’s personality, culture, and overall health. With the diversity in hair types and concerns, the hair care industry has developed a wide range of products designed to cater to specific needs. With the development of novel formulations in hair care products for both cosmetic and medicinal needs, testing their safety and efficacy before human application is essential. Moreover, these hair care products must adhere to the regulatory standards set by health authorities such as the U.S. Food and Drug Administration (US FDA), European Cosmetic and Perfumery Association (COLIPA), Central Drugs Standard Control Organization (CDSCO), etc., which involve monitoring the stringent testing for safety and efficacy before being marketed to consumers. Hair product safety and efficacy testing utilizes pre-clinical and clinical models to assess whether the product delivers the promised benefits, such as improved hair growth rate, hair loss prevention, moisture retention, etc., through laboratory measurements and user feedback. These models range from two-dimensional (2D) monolayer cultures of primary cell types in hair follicles (HFs) such as dermal papilla, dermal fibroblast outer root sheath keratinocytes, or ex vivo organ cultures of isolated HFs to wild-type or transgenic animal models. This chapter discusses the available experimental models and progress made in evolving new models to observe the impact of tested hair products on different stages of hair cycles. Further, the critical issues associated with hair health, the rationale, advantages, and shortcomings of the developed experimental models for hair care products, and the resulting progress in their development have also been discussed.