Efficacy testing for hair care products

For the efficacy testing of hair care products, a number of methods are available. Scanning electron microscopy and atomic force microscopy are most suitable for surface evaluation; the swelling properties in the course of a treatment are determined using a fiber-swelling analyzer, and the luster may be reliably determined by means of a multiangle goniophotometer. Further, surface tension is a suitable method to evaluate the hydrophilic/hydrophobic properties of a hair section, and is sensitive enough to indicate the individual hormone cycle.