There are some “Golden Standards” when choosing a study design in the clinical trial arena. A double blind design occurs when both parties, including the subjects and the study administrators, are unaware of who is the testing group and who is the controlled, or placebo group. A single blind study design is when one of the parties (subject or investigator) knows who the treatment group is and who the placebo/controlled group is. The double blind design can help eliminate bias, as both parties are “blinded” as to who is receiving the treatment formulation.
When testing cosmetic formulations, an active ingredient in a formulation is usually being tested. However, once that formulation reaches the manufacturer, the manufacturer is usually interested in the formulation as a whole, not just the active ingredient. Johann W. Wiechers, Ph.D., suggests using a single blind approach when testing the affects of an active ingredient in a formulation, as it will more accurately answer the end questions for the manufacturer: is the active formulation active?