An 8-week face-split study to evaluate the efficacy of cosmeceuticals using non-invasive bioengineering devices.

BACKGROUND/AIMS: Even with the increasing demand for functional cosmeceuticals in the recent years, objective standard criteria for assessing their efficacy are currently incomplete at best. In this 8-week face-split study, in which we topically applied high-priced cosmeceuticals on one side and more affordable cosmeceuticals on the other side of the face, we compared the efficacy of these two products using non-invasive bioengineering technology. METHODS: We assessed the efficacy of a skin-whitening and an anti-wrinkle cosmeceutical product on 25 and 19 healthy female volunteers, respectively. In a single blind split setting, each participant received an 8-week topical application of high-priced cosmeceuticals to the left side of the face, and cheaper cosmeceuticals to the right side. Then, the subjects' biophysical parameters were measured for an objective evaluation of the results. This was followed by a questionnaire to obtain a subjective assessment. RESULTS: There was no significant difference in the change between the high-priced cosmeceuticals and the more affordable cosmeceuticals. At each measured site, there were variable changes including skin improvement and aggravation at the end of study. The subjective questionnaire demonstrated also that the participants perceived no difference in the efficacy between the two products. CONCLUSIONS: Our results showed that there were no significant differences in the skin biophysical parameters following the application with high-priced functional cosmeceuticals or less expensive cosmeceuticals. The subject failed to differentiate between the two products. The development of objective standard criteria for assessing its efficacy is essential.