Every claim that appears on the cosmetic product label, on the website where the cosmetic product is presented, in TV commercials etc. has to be substantiated unless it's a clear exaggeration or it's obvious for the type of the cosmetic product. It is a responsible person's task to ensure that all of the claims made regarding the product are substantiated.
In the labelling, making available on the market and advertising of cosmetic products, text, names, trademarks, pictures and figurative or other signs shall not be used to imply that these products have characteristics or functions which they do not have. (EU Regulation 1223/2009, Article 20)