Summary Background Dietary or supplementary intake of nutrients and other ingredients positively affects skin appearance. Aims Evaluate a multicomponent nutritional supplement on photoaged skin. Patients/Methods This multicenter, double‐blind, placebo‐controlled trial randomized healthy 35‐ to 65‐year‐old women with Fitzpatrick skin types I– IV and Glogau classification types II – III to a multicomponent nutritional supplement or placebo for 24 weeks. The primary endpoint was Investigator Global Assessment of overall facial appearance at week 24. Secondary endpoints included investigator‐ and subject‐rated assessments of the face, décolletage, and hands; facial photography assessments (conducted by an independent panel of dermatologists); and instrumental measures. Analysis of variance was used to assess between‐group differences ( P ≤ 0.05). Results Of 194 randomized subjects, 171 completed the study. Subjects had a mean age of 53 years and were primarily white (81%), had Glogau II (58%) and Fitzpatrick III (45%; significantly more supplement subjects had Fitzpatrick III [54%] vs . placebo [35%]; P = 0.039). At week 24, Investigator Global Assessment of overall facial appearance was numerically but not statistically better for supplement over placebo (mean difference: 0.14 [95% confidence interval: −0.16–0.44]; P = 0.358). A significant treatment‐by‐site interaction (P = 0.073) was observed; by‐site analyses revealed a significant difference at one of three geographical sites for supplement vs . placebo ( P = 0.001). Differences on secondary endpoints were generally not significant. Conclusions In the first multicenter study conducted with this multicomponent nutritional supplement, no significantly greater effects vs . placebo were observed on the primary endpoint, perhaps because of significant between‐site variability.

Although the FDA does not require documentation of efficacy of dietary supplements, prospective clinical studies, including randomized controlled trials, have been conducted with individual micronutrients alone and in combination with other ingredients for promoting skin health. Proposed mechanisms include antioxidation, anti-inflammation, photoprotection, collagen formation, reductions in matrix metalloproteinases, and other effects on photoaging. Literature searches were conducted to identify clinical trials assessing multicomponent dietary supplement formulations on photoaging outcomes. Sixteen studies of various nutrient and non-nutrient ingredients, including essential micronutrients (vitamins, minerals), plant extracts (polyphenols, carotenoids), and marine- or animal-derived ingredients, were identified. Studies were single center, 2-12 months in duration, primarily enrolled women, and evaluated numerous outcomes, including investigator/subject assessments and instrumental/objective measures. Methods to control for potential confounders were implemented in some studies, including limiting sun exposure, cosmetic procedures, and changes in dietary habits/body weight. Given the range of different products, clinical/methodologic heterogeneity, insufficient detail in reporting, and lack of comparable outcome measures, quantitative analysis of results was not possible. Results of individual studies revealed significant improvements from baseline for the dietary supplement group(s) on ≥ 1 endpoint across all studies; significant differences from placebo were observed in 7 of 12 controlled studies (although only 1 study designated a prospectively defined primary endpoint). Most products had only been tested in 1 study; confirmatory studies were rarely conducted per the publicly available literature. Meaningful assessment of dietary supplements, which typically contain nutrients found in the diet, requires unique methodologic considerations and endpoints appropriate for measuring changes that are more subtle and gradual than those observed with topical/injectable products. Although definitive conclusions could not be drawn from the existing evidence, available data are supportive of beneficial effects of oral multicomponent supplements on skin health. Confirmation of positive effects with the same formulation/endpoint from more than a single study/investigator is needed.