Stearic acid.
Say what?! Is that for cleaning out toilets? That was what I first envisioned when I heard the name. Couldn’t have been further off track!
This is a new ingredient I recently discovered and experimented with, for using in balms, soaps and creams.
So what is it and why should you care:
Stearic acid is an isolated fatty acid used to thicken and harden lotions, salves, balms and soap. Stearic acid occurs naturally in shea butter and cocoa butter.
It stiffens and hardens products without the waxy feel you get when using beeswax or other waxes. It creates a more creamy buttery texture rather than the weight and tack of waxes.
Stearic acid is oil soluble so we melt it in our oil phase. It’s melting point is higher than beeswax 69.3C, 156.7F.
It has a slow to medium absorption speed.
It has a long shelf life and is inexpensive. (Source)
It has been shown to protect skin's surface against water loss and help shore up skin's protective barrier. (Source)
In addition it is used as a surfactant to help wash away excess oil and dirt from the skin.
The Food and Drug Administration (FDA) includes stearic acid on its list of direct food additives considered Generally Recognized As Safe (GRAS). The Cosmetic Ingredient Review (CIR) Expert Panel evaluated the scientific data and concluded that stearic acid is safe for use in cosmetic products. (Source)
The EWG skin deep database gives it a safety score of 1. Which is the best. (Source)
Stearic acid can be both animal and plant derived so if that is of significance to you check the sourcing of your supplier. This is a great vegan thickening agent for vegan formulations to use in absence of beeswax.
Here is a creamy massage balm, recipe to come, that I made using stearic acid.