What is a moisturizer and why does a bottle of moisturizer have so many ingredients? The goal of this post is to give you some guidance on what kind of moisturizer or cream to choose for your skin needs.
A moisturizer is an emulsion of water and oil. Since water and oil like to separate, you need a stabilizer to keep them together. So thus far, you need water, an oil based substance, and an emulsifier.
Most moisturizers use petroleum and mineral oil for the oil. You might see some other oils occasionally, like sweet almond. Petroleum and mineral oil are widely used because they are by-products of the petroleum industry and therefore, super cheap. Other names for mineral oil and petroleum are paraffin and petrolatum. Many people are turned off by petroleum in skin care products - it is so un-sexy. So some companies have become creative and use the actual chemical names for these things. So what exactly is mineral oil? It is not an oil loaded with minerals (Calcium, Magnesium etc.) for sure!!! It is basically a mixture of long chain alkanes. Alkanes are hydrocarbons - ex. Methane, Ethane, Propane, Butane, Pentane, Hexane, Heptane, Octane, Nonane, Decane - you get the idea. Mineral oil has a bunch of alkanes with a lot of carbon atoms. So if you see Oil of Olay Complete, nowhere does it say petroleum or mineral oil. Instead, you see isohexadecane - a hydrocarbon with 16 carbon atoms. Neutrogena sell a Hydro Boost Gel-Cream Eye for $19. It has C13-14 Isoparaffin - more large and branched alkanes.
In your moisturizer, you will find stearates, cetyl alcohol, lecithin, or stearic acid. These are your emulsifiers - to stabilize the water/paraffin mixture. Some other questionable emusifiers are ethers of lauryl aclcohol - Laurethx where x is a number. Another emulsifier you might see is pareth-7.
The next issue is how the product feels on the skin. Most people do not like oily stuff on their skin. So in comes a silicone polymer - the most common polymer you will find is dimethicone. These polymers make the experience of lotion spreading very good - smooth, fills in the crevices and lines etc.
What else? A common ingredient you will find is polyacrylamide or polyacrylate. This polymer has a hazy reputation in terms of health and is used as binder in many lotions. It forms a film on skin that has a lubricating effect. The issue with this polymer is that it could break down into acrylamide that is supposed to be a class 1 carcinogen.
Finally, since a lotion is about 70% water, it can be a fertile breeding ground for bacteria. So you need a preservative or antimicrobial. There are several things used for this - paraben, methylparaben, DMDM hydantoin, chlorphenisen. Paraben and methyl paraben are most commonly used and have been in the notorious spotlight for questionable impact to health.
So that's about it. Next time you purchase a lotion, look at your ingredients and make choices you are comfortable with. I will end with my opinion. Most commercial lotions are the same - bold statement but true from a chemical standpoint. They all have some form of alkane, fatty alcohol, water, silicone, and preservative - in other words a synthetic chemical soup. Most commercial lotions contain ZERO chemicals that your body produces - like fatty acids, triglycerides, and wax esters. So next time you purchase a lotion for your body or face, make conscious choices - read the ingredients. If you are disgusted by this, go look for natural alternatives - go to health food store and get some shea butter until you figure out choices.