Nu Skin has a philosophy of using the best natural ingredients while avoiding harmful fillers. They combine natural ingredients with innovative technology to produce high-quality personal care products. Their formulas utilize beneficial natural ingredients identified by science. Nu Skin's research is backed by an expert advisory board and a partnership with Stanford University. They emphasize selecting ingredients through a rigorous 6S quality process focusing on safety, standardization, and substantiation to ensure product quality and efficacy. While Nu Skin does not test cosmetic products on animals, animal research may be necessary to substantiate the safety and efficacy of nutritional supplements, as required by some regulatory agencies.