Encyclopedia · oil or butter
Shea butter
A heavy plant butter widely used on coily hair, with no fibre-science data behind it.
What it is
Fat from the nut of the shea tree of West Africa. It is solid at room temperature and rich in stearic and oleic acid. It is a cosmetic ingredient, and the Cosmetic Ingredient Review panel published a safety assessment of shea-derived ingredients in 2024.
How it works
It is an occlusive emollient that coats the fibre and slows water loss. We found no mechanism study on hair.
What the studies show
- We found a short survey letter on shea butter use in Nigerians and a safety assessment, but no fibre-science data (see oils and hair).
- No randomised head-to-head human trial of hair oils or butters exists.
How it's used in studies
Traditionally it is applied as a butter after a leave-in and water on damp hair, in "LOC/LCO" style layering, which has not been trial-tested.
Side effects and safety
Low risk is expected. It is heavy and can build up.
Bottom line
Useful as a heavy sealant for coarse, curly, high-porosity hair, on personal preference. There is no trial evidence, and whether sealing over water improves retention is untested. We are very unsure of any benefit beyond feel.
Studies 0
No studies are listed for this page yet.
Related
- Avocado oilA rich oleic-acid oil common in deep conditioners, with no hair-fibre or clinical hair studies found.
- Coconut oilThe best-studied hair oil; in lab work it cut protein loss and fatigue damage when used before washing, but almost all studies come from coconut-oil sellers.
- Oils and hairOils coat hair and some enter it, which can cut damage from washing, but they do not repair split ends or add moisture.