"Well compared to what you eat, it is pretty obvious that cosmetics can only make a tiny contribution to what is in your body. The most dedicated of beauty junkies is not going to apply more than a few grammes of product a day. Even if was all absorbed it would not even equal a mouthful of food.
However most of what you apply is simply not absorbed. Rest assured the skin is an extremely good barrier. That is why diabetics have to inject insulin rather than letting it soak through the skin and why snakes have to bite you in order to poison you. This is actually a great shame for the pharmaceutical industry because transdermal patches would be a great way of delivering drugs if the skin didn’t do such a great job of keeping stuff out.
Even if they did get through the skin the bulk of chemicals used in cosmetics are not very different to those you eat in any case. A chemical like say glyceryl monostearate might sound scary if you don’t know what it is. But it is simply a fraction of a vegetable oil with a very slight chemical modification – and modification that your body carries out too. The next time you eat some fried food you will probably be eating more glyceryl monostearate than would get into your body from a lifetime of applying skin creams.
Most cosmetic ingredients are derived from natural sources. This has always been the case. If they do get into your body, you have enzymes that can deal with them. Your liver’s main reason for existing is to deal with toxins and it has plenty of tools to do the job. This is just as well because even a very organic diet has plenty of toxins in it (or maybe especially an organic diet). Fortunately we have evolved to deal with them.
I have said that the skin is a good barrier, but there are some chemicals that have the right properties to go through it. But there aren’t many. Nicotene is one, which is why you can buy nicotine patches. Caffeine is another. But very few drugs are available as patches because very can be made to penetrate the skin. Very very few of the materials used in cosmetics will get through the skin. But even then, just getting through the skin is not enough for a chemical to accumulate. If it is metabolised then the body will get rid of it quickly. We are all familiar with how quickly the body deals with caffeine. I am writing this late at night and I am well aware that my last dose is in need of replacement.
So it is far from obvious that any cosmetic raw material accumulates in the body. I can only think of a handful of materials that even have a chance to do so. Of those only the parabens are not metabolised extremely quickly. (I don’t want to talk about parabens again, after 8 recent blog posts my regular readers must be fed up of them by now.)
I have done some work trying to deliberately improve penetration through the skin. It is an extremely hard thing to accomplish. So in a nutshell, the answer to Lynne’s question about studies of the long term effects of accumulation of cosmetic raw materials in the body is that we don’t know because it doesn’t happen."
- Source: Do Chemicals in Cosmetics Accummulate in Your Body by Colin Saunders - PersonalCareTruth.com