INTRODUCTION
The increasing role of online information in patient decision-making requires that dermatologists be prepared to discuss unsubstantiated dermatologic treatments that patients encounter online.1-4 An Instagram analysis found that 68% of influencers with over 40,000 followers who post dermatology-related content have no medical credentials, while only 4% were dermatologists.5 With 93% of skin influencers sharing self-promoted or sponsored content, there is substantial capacity for financial conflicts of interest.5
These trends have been accompanied by an increased interest in natural skincare ingredients.6,7 Bakuchiol is a plant-derived molecule marketed as a natural, mild alternative to retinoids with demonstrated anti-tumor and anti-viral activity. Bakuchiol has been tested in epithelial carcinoma and melanoma cell lines, inhibits melanogenesis in cultured human melanocytes, and has been explored as a treatment for psoriasis.8-12 Bakuchiol's biologic activity is superficially understood but may be due to the modulation of inflammation and oxidation.13-19 Methodologic flaws in human clinical trials using bakuchiol for the treatment of facial aging have been reported.20 A recent review of evidence for bakuchiol's use in dermatology did not capture multiple published human clinical trials.21
The objective of this systematic review is an updated analysis comprising all human clinical trial data on the use of bakuchiol in topical formulations for the treatment of facial skin disorders. A broad assessment of evidence for bakuchiol's use as a dermatological treatment will inform its future use in cosmetic dermatology.
These trends have been accompanied by an increased interest in natural skincare ingredients.6,7 Bakuchiol is a plant-derived molecule marketed as a natural, mild alternative to retinoids with demonstrated anti-tumor and anti-viral activity. Bakuchiol has been tested in epithelial carcinoma and melanoma cell lines, inhibits melanogenesis in cultured human melanocytes, and has been explored as a treatment for psoriasis.8-12 Bakuchiol's biologic activity is superficially understood but may be due to the modulation of inflammation and oxidation.13-19 Methodologic flaws in human clinical trials using bakuchiol for the treatment of facial aging have been reported.20 A recent review of evidence for bakuchiol's use in dermatology did not capture multiple published human clinical trials.21
The objective of this systematic review is an updated analysis comprising all human clinical trial data on the use of bakuchiol in topical formulations for the treatment of facial skin disorders. A broad assessment of evidence for bakuchiol's use as a dermatological treatment will inform its future use in cosmetic dermatology.
MATERIALS AND METHODS
A comprehensive search of Cochrane Library, PubMed/MEDLINE, EMBASE, and Web of Science was conducted on or before August 28, 2022, using the search terms "bakuchiol" and "UP256." Cochrane Library PRISMA guidelines were used for de-duplication, inclusion, and exclusion processes.22,23 Inclusion criteria were human clinical trials with bakuchiol treatment of skin and English language. Exclusion criteria were basic science articles, epidemiologic studies, case reports, reviews, meta-analyses, skin explant studies, skin cell assay studies,
