Many products contain added vitamins like A, D, E, K, and others. These vitamins are essential to healthy hair and skin, but there is no definite experimental evidence to show that placing vitamins, and many other additives, on the skin has any benefits, because it is quite possible that the skin does not absorb and use them. Basically, cosmetic label statements which promote the addition of an ingredient into the product as beneficial need to be taken with a grain of salt, as many are either not potent enough or are not proven to have a real effect.
Another common claim of cosmetic labels is that they are formulated to have some trait that appears attractive. A very typical example is the phrase "hypoallergenic." For people with sensitive skin, hypoallergenic cosmetics sound like a blessing, because the word "hypoallergenic" means that the cosmetic is less likely to cause an allergic reaction to the user. Then again, there are absolutely no FDA (Food and Drug Administration, the federal agency which regulates, among other things, cosmetics) regulations concerning the use of the word "hypoallergenic." In other words, there is no set definition for hypoallergenic, which leaves the decision of whether or not the product really causes less allergic reactions completely up to the company.
The term "dermatologist-tested" only means that a dermatologist has run tests to determine if the product causes less reactions in general. This does not mean that the cosmetic actually does cause less reactions, only that it has been tested. Of course, some companies really do try to make their products less likely to induce allergies by conducting lab tests, but just because the cosmetic is labeled as "hypoallergenic" or "dermatologist-tested" does not mean that it will not cause an allergic reaction.
