Glycerin is a natural product of the soap making process. However, many commercial soap manufacturers remove the glycerin to create other products such as moisturizing lotions.
Glycerin soap is gentler on skin than most soap, making it a good choice for people who have particularly dry or sensitive skin. Glycerin soap also has a lower pH than other soaps, which helps the skin retain its natural moisture. Since glycerin is hygroscopic, it may also help moisturize the skin by attracting water from the air.
Glycerin soap comes in both bar and liquid formulas. Soaps made from vegetable oil glycerin have the benefit of being vegetarian or vegan, for those who object to using animal products.
In spite of its benefits, glycerin soap generally does not lather up as well as other soaps and may dissolve if it is left in water or attracts too much moisture from the air. Glycerin soap is also more expensive than most other types of soap. Hand-crafted glycerin soaps that contain all natural ingredients, rather than synthetic detergents, may be significantly more expensive than those that are mass produced.
To keep glycerin bar soap from melting, it should be stored in a cool, dry place before use and on a soap dish that has holes for drainage.
Probably the most common use of glycerin is in soap. Actually, glycerin is a natural by-product of soap production. When fat is combined with a base and water, soap and glycerin are formed. Our ancestors simply left the glycerin in the soap. But modern manufacturers remove the glycerin to dry the bars. They use the glycerin in other cosmetics. Natural or homemade soaps are often very high in glycerin. Glycerin helps the skin maintain a natural water balance without oils.
Glycerin soap makes a great acne cleanser because it keeps the skin from drying out without clogging the pores. Used alone, or with a facial brush or washcloth, glycerin soap clears oil, dead skin, and other contaminants.
According to Dr. Wendy Bollinger Bollag of Vanderbilt University, there is evidence to suggest that glycerin may aid in the healing of skin diseases such as psoriasis and eczema. The water-retaining benefits of glycerin appear to contribute to healthy skin cell maturation.
Glycerin alone, or mixed with other compounds, makes a great moisturizer. Because of its ability to draw and hold water, it prevents skin from over drying. Glycerin moisturizes without clogging pores.