Abstract: A method of assessing the suitability of a set of cosmetic and/or nutricosmetic and/or skin care products for an individual. The method comprises testing a sample of genetic material for an individual to identify the presence or absence of single-nucleotide polymorphisms at a predefined set of single-nucleotide locations. One or more weights for each location are identified in dependence upon the presence or absence of a single-nucleotide polymorphism at the location and the single-nucleotide location weights used in order to determine a product score for each of said products, a score being indicative of the suitability of a product to the individual.