by Dr. Irene Reyzis
Short answer: yes!
It is possible for ingredients and chemicals to penetrate the skin. Some even make their way into the bloodstream if they are absorbed into deeper layers where blood vessels exist. A classic example is nicotine from nicotine patches, or menthol from muscle rubs.
However, not all compounds are able to penetrate deeper than the skin surface. It depends on several factors like the size, chemistry of the compound, and the skin area where the compound is applied. These factors make a difference in how likely a chemical is to penetrate the skin and be absorbed by the body.
Implications of ingredient and chemical penetration
Whether or not ingredient penetration is a good thing or a bad thing is a matter of circumstance with no clear black-or-white answer. There are plenty of scenarios where penetration of ingredients is desirable! Think collagen-boosting and skin-soothing actives in your skincare products.
On the other hand, plenty of unwanted chemicals may be absorbed into the body from consumer products when they come into contact with skin.
Regulating agencies like the FDA deem that potentially harmful chemicals are safe for use in cosmetics below certain levels. However, it would be the preference of many health-conscious consumers to avoid potentially harmful chemicals altogether. This is especially the case with cosmetics where products are applied to the body surface as a direct pathway of chemical absorption.
Common penetration enhancers in cosmetics
The following is an incomplete list of ingredients that can act as penetration enhancers in cosmetic products. This means they change skin chemistry in a way that absorption of other ingredients and chemicals is increased.
- Propylene glycol
- Polyethylene glycol (PEG) and related ingredients
- Polysorbates like polysorbate-20, etc.
- N-methyl pyrrolidone and related ingredients
- Alcohol (Ethanol)
- Cetyl alcohol, cetearyl alcohol, etc.
- Fatty acids like stearic acid
- Sodium Hyaluronate
By themselves many of these ingredients are actually good for your skin, for instance glycerin, lecithin and fatty acids. However, in products that include these ingredients, any unwanted chemicals or baddies also present may absorbed by the skin in greater amounts. In other words, more of the bad stuff is getting into the body than usual.