The first group of products that we’ll review will be cleansers. If you use nothing else on your skin, I know you do use a cleanser! There is a huge array of products out on the market, with many different price points, different additives and different formulations.
Quick, read the epidermis post if you haven’t yet (or re-read it if you have, I added a few things) before we start!
How Soap Works
All cleansers work the same way, whether a $1 bar of soap or a $100 bottle of La Mer cleanser. Really! In order to both get rid of oils, sweat and dirt on the skin while making the whole thing water soluble, surfactants are used. Basically, look at the left side of the picture above. This is the basic soap molecule. There is a long chain of non-polar (neutral) atoms (that part that looks like a tail) and this part is attracted to the dirt, oil, etc. The other end (the polar, or charged end) is attracted to water. So, lots of little soap molecules will surround the piece of dirt, oil or whatever; see the right side of the picture. Note how they surround the offensive bit with their non-polar end, and the polar (water attracting) end is out into the water, allowing the whole thing to be water soluble.
Note that not all cleansers are technically “soap.” There are soaps and detergents, the difference is the way in which they are made, in addition to their pH. Soaps tend to be more alkaline, and as such may result in more drying and irritation of the skin. Both work through the surfactant mechanism I just described, and there are different fats and additives that compose the rest of the cleaners.
The whole thing sounds pretty simple, doesn’t it? Well, there are definite downsides to this whole process.
1. Redness and Irritation: The soap molecules may surround and damage the Keratin within the skin. This allows the Keratin to swell and become overhydrated, damaging the skin and it’s barrier function. In turn, this allows the soap to penetrate more deeply into the skin, where they interact with nerve endings and are attacked by the body’s immune system, resulting in irritation, redness and itching.
2. Dryness: The soap molecules may remove some of the lipid between the cells of the Cornified Layer, and may also remove some of the moisturizing molecules within the cells of this layer as well.
3. Tightness after Washing
The extent to which a soap is irritating depends upon several thing- the potency of the surfactant, the pH of the soap (higher pH=more basic/alkaline=more irritating, irritating soaps will be in the range of 9.5-11), and rinsability. All of these effects are minimized by adding moisture through depositing lipids and humectants (things that attract moisture) into the skin. As well, artificially created surfactants (also called syndets) are less harsh on the skin than more naturally created surfactants.
Types of Cleansers
There are many fomulations of cleansers out of the market today, and often the only way to discover what type of cleanser you have is to check the label!
Most soaps can be easily divided in terms of their composition, I find this the easiest way to think of them.
1. Soap: Old fashioned soap, pH is usually 9-10
2. Combars: Combines soap with “surface active agents” with a pH 9-10
3. Syndet: Synthetic detergents rather than than mostly soap surfactants, they usually are