EU / US and UK registered product. What is it ? PHA or poly hydroxy (fruit) acid are chemical exfoliants, and are considered second-generation AHAs. Why is it better ? Their difference lies within their molecular structure.The molecules of PHAs are bigger and therefore cannot penetrate as deeply as AHAs and BHAs; they work exclusively on the surface, are less irritating than their AHA and BHA counterparts. An additional benefit of PHA is that skin does not become more photo-sensitive, or susceptible to damaging UV rays. At last , PHA will hydrate the skin. What does it do ? They exfoliate by breaking up the bonds that glue the superficial layer of dead skin making the skin brighter and radiant. Visible results in 1-2 applications. How to use ? Up to 2 times a week. Apply 2-4 drops to the face and massage gently .Wait 15 min (so the acid can do its job). This serum is preserved using sodium levulinate (extracted from wood) and sodium anisate (star anise spice) .