Why do Elsom Research product labels say “do not mix with non-Elsom products”?
We assume you are interested in our products because you expect them to have some good effect on your appearance. We have chosen and combined our ingredients carefully to be as beneficial as possible, alone or in combination with our other products; by adding another product (for example, by using our vitamin serum but someone else’s moisturizer), you are adding an unknown set of ingredients and we have no way to predict or compensate for their impact; you are likely to find that neither product is as effective as it could be. If you must use a product from another manufacturer, please at least avoid the many products containing mineral oil, which is very unhealthy for skin.
