When you lather up and scrub down, you probably aren't thinking about how the soap you're using came to be. Yet it's important to understand the chemistry of soap. Knowing what ingredients are in daily contact with your skin can help you sort through the good and the bad of face soaps.
At the microscopic level, soaps are made up of a chain of hydrocarbons. One end of this hydrocarbon chain attaches to grease and oils on your skin while the other end of the chain bonds with water [source: The Soap and Detergent Association]. When you rinse with water, the soap and any attached impurities wash away.
Traditional body soap is the result of a chemical reaction between a fat or an oil and an alkali such as sodium or potassium salts. When the fats and oils are heated and combined with the alkali, they produce a soap plus water and glycerin [source: The Soap and Detergent Association].
Glycerin is a byproduct of soap making. That is, it is created naturally in the soap-making process. Soap companies remove the glycerin from soap to create a low-cost basic bar soap. However, when glycerin is left in soap, it can help the skin stay soft by attracting moisture to it. Soaps with glycerin work well as face soaps, except in cases of very oily skin [source: American Academy of Dermatology].
Other ingredients to look for in face soap are emollients and humectants, which act as moisturizers. If your skin is very oily or prone to breakouts, a cleanser with benzoyl peroxide can help, though it may cause some irritation.
Now that you've got the skinny on soap making, keep reading to find out which face soap is right for you.