What is Stearic Acid?
Stearic acid is a saturated fatty acid with the lipid number C18. The fact that there is no colon with a number after it means that there are no double bonds. This means that stearic acid isn’t easy to break and isn’t going to go rancid easily. Oils high in stearic acid generally have shelf lives of at least two or three years. Stearic acid is waxy and solid it is therefore no surprise to learn that its name comes from the Greek word “steatos” which translates to mean tallow. Stearic acid helps the skin to retain moisture and to stay flexible. It also assists with damage repair.
Stearic acids are widely used in manufacturing including: cosmetics, soap, detergents, and lubricants. Esters of stearic acid are used in the saponification process (a process of producing soap from fat and lye). It is used to thicken and emulsify lotions and creams. The stearic acids used in these products is a derived product, often from animal fat.
How does Stearic Acid Help Our Skin?
Stearic acid is found naturally in the outer protective layer of our skin, and is a fundamental building block in the lipid layers of the skin. These layers form a barrier against pathogens and germs and help retain our skin’s natural moisture. Note that the naturally occurring stearic acid in the butters and oils listed below are good for your good. This is different than the chemically derived extracts that are used in manufacturing cosmetics. Seeing “stearic acid” as an ingredient on a label is not a good thing. What you want is to get the stearic acid naturally in the ingredients in your products. It is similar to how you can think about vitamins. If the food you are eating is naturally high in vitamins and minerals, you won’t see them listed as an ingredient. They can be listed in the nutritional profile, but because they are a part of the food, they are not an actually added ingredient. They don’t need to be! And when you see vitamins or minerals as ingredients, then you know that they are synthetic. It is always better to get the natural form the substance in the food rather than having to add a synthetic ingredient. So look for products that contain the butters and oils rich in stearic acid, rather than looking for products which contain stearic acid.
What Oils are High in Stearic Acid?
Stearic acid is more prevalent in animal sources than plant sources for the most part. The one exception to this are the butters, such as mango butter and shea butter. There are many other plant oils which also contain stearic acid, but in much smaller amounts.
Some of the oils high in Stearic acid include:
- Illipe butter (45%) Has a shelf life of about 2 years
- Kokum butter (42%) Has a shelf life of about 1 year
- Mango butter (42%) Has a shelf life of about 2 to 3 years
- Shea butter (40%) Has a shelf life of about 2 years
- Cocoa butter (35%) Has a shelf life of about 2 to 5 years
- Tamanu oil (13%) Has a shelf life of about 10 to 14 months
- Avocado oil (4%) Has a shelf life of about 1 year