You'll read all kinds of things shea butter can do - reduce irritation, reduce redness, protect skin, regenerate cells, heal wounds, moisturize skin, prevent premature aging, and act as a sun screen - but how much of it is true and how does it do it?
Shea butter contains a ton of Vitamin E in the form of tocopherol (100 to 150 ppm) and tocotrienols (110 to 175 ppm) that acts as a natural anti-oxidant for your skin and the butter, so it's softening to our skin. It contains at least 8 various catechin compounds, which offer anti-bacterial properties to shea butter.
The phytosterols in shea butter contain cinnamic acid esters (that's the pretty molecule above), which can act as a UV protectant (I've seen it said that 15% shea butter has an SPF of 3, although I don't recommend using it in this capacity). This offers some of the healing properties associated with shea butter because these esters can reduce superficial irritation and redness of the skin.
Shea butter contains allantoin, which is approved by the FDA as a barrier ingredient to temporarily prevent and protect chafed, chapped, cracked, or windburned skin by speeding up the natural processes of the skin and increasing the water content.
We find a lot of oleic acid in shea butter - 40 to 55% - which offers moisturizing and regenerating, anti-inflammatory, and softening properties. It is well absorbed by the skin.
We also find a lot of stearic acid in shea butter - 35 to 45% - which offers improved moisture retention, flexibility of the skin, and skin repair.
Shea butter melts at 29˚C to 34˚C. The more refined, the softer it is, and the lower the melting point. It acts as an occlusive to keep water in and prevent the elements from destroying our skin!
So does shea butter live up to the claims? Which ingredients contribute to the amazing qualities attributed to shea butter?
- Reducing redness - Cinnamic acid esters.
- Protecting skin - Allantoin, mechanism of occlusion.
- Regenerating cells - Allantoin, oleic fatty acid, stearic fatty acid.
- Healing wounds - Allantoin.
- Moisturizing skin - Mechanism of occlusive, polyphenols, oleic fatty acid, stearic fatty acid.
- Sunscreen - Cinnamic acid esters
- Softening - Polyphenols (tocopherols and tocotrienols), oleic fatty acid.
- Anti-bacterial - Polyphenols (catechins).
- Irritation - Cinnamic acid esters.
- Anti-inflammatory - Oleic fatty acid, cinnamic acid esters,
- Flexibility of the skin - Stearic fatty acid.
Preventing premature aging is definitely a hard one to prove. I don't like this claim - it's subjective and can't really be measured the way we'd measure how much moisture leaves our skin or how long it would take for a wound to heal. So I'm going to call that one unprove-able (is that a word?) and leave it there.
Shea butter has about a two year life span - thank the tocopherols and saturated fatty acids for that! - and can be used at up to 100% in your creations. It is a greasy feeling butter, so if you're not a fan of the very oily feel, you might want to consider using it at lower levels. If you love an oily feeling butter, then shea butter is a great choice! Shea butter can be used in most - if not all - bath & body applications from lotions to hair care to bath bombs to anything you want, with the possible exception of surfactant based things like bubble bath or body wash as it will reduce the foam. (Or you can use fractionated shea oil...more about this soon!)
And why does shea butter go grainy in some creations? Shea butter fractionates when heated, meaning the various fatty acids separate. Given these fatty acids have different cooling points, some will harden more quickly than others, resulting in some fatty acids being solid while others remain liquid! This means we want anything containing shea butter to cool very quickly to ensure the various fatty acids solidify at the same time. So an ice bath, popping it into the fridge or freezer, or not melting it at all is generally a good thing for shea butter.
Join me tomorrow for some super happy fun formulating with shea butter!