An area of product design which is not widely understood is that of objective in vivo testing, i.e. testing of the effects of products directly on the skin. It is an area where design and execution of study is key to obtaining accurate and robust data. These techniques are used from the moment of developing a new product in the lab to generating claims for a product being sold in the market. There are a wide variety of skin testing methods, each addressing different aspects such as hydration, colour, oiliness etc.
Outlined here is a background on these methods. There are a lot out there, so this list is not exhaustive. Some of the techniques I have and am doing ongoing research with (such as the Corneometer, Sebumeter, Chromameter and Photography) and others I currently don’t have but can access if needed. I have practical experience with use of all of the ones I’ll talk about here, along with the designing and running of studies which utilize them.