Whether it's a cream, gel, emulsion or oil, all cosmetics have the same basic structure: one or several active ingredients that ensure the product is effective, an excipient to transport these ingredients, and additives to perfume, preserve, and lather the product and stabilise its pH. These different ingredients might come from plants, animals, minerals or could even be synthetic. Yet, as we well know, nature's resources are not infinite. Chemistry comes to the rescue to protect natural resources and save the cosmetics industry! Chemistry is far from the bad guy of the story: it replaces natural ingredients by reproducing these molecules found in nature, either through chemical synthesis or biotechnology. But that is not all: chemistry also steps in as part of our cosmetics when our body can no longer produce enough of certain molecules, such as collagen or hyaluronic acid.