Pilot Study on the Effects of a Cosmetic Serum Containing Niacinamide, Postbiotics and Peptides on Facial Skin in Healthy Participants: A Randomized Controlled Trial

The literature describes niacinamide, but also postbiotics and peptides, as ingredients that improve skin barrier function, but also affect melanin and sebum levels in individuals. However, the combined effects of these ingredients in a single cosmetic serum have not been sufficiently investigated. Therefore, the aim of this randomized controlled study, conducted at the University of Split School of Medicine (Croatia), was to evaluate the effects of cosmetic products containing these active ingredients. This study was registered with ClinicalTrials.gov (NCT06189105) and has been completed. Primary outcomes were the levels of trans epidermal water loss, skin hydration, erythema, melanin, and sebum, all measured in 25 healthy Caucasian participants. Significant differences between hydration levels were observed at week 4 (61.0 ± 11.2 vs. 68.6 ± 13.3 AU, control and intervention). Moreover, a significant decrease in erythema values from the first to last measurement in the intervention group was observed, (379.9 ± 106.8 vs. 333.6 ± 73.5 AU, baseline values and week 4, intervention group). Interestingly, both the increase in skin hydration levels and the decrease in skin erythema after niacinamide serum application were significant in study participants who did not use sun protection products. It is well known that ultraviolet radiation has detrimental effects on human skin, and our results suggest that niacinamide could help counteract these effects.