Shea butter

What it is

Shea butter is pressed from the nuts of Vitellaria paradoxa, a West African savannah tree used on skin for centuries. It is mostly oleic and stearic fatty acids, which soften and seal the skin, plus an unusually large "unsaponifiable" fraction of triterpenes, vitamin E and plant sterols¹. Those compounds give shea its anti-inflammatory activity in laboratory tests¹. Unrefined shea is ivory to yellow and smells nutty; refined shea is white and nearly odourless, and has lost some of them in processing.

What the evidence says

Evidence: limited. Laboratory studies show genuine anti-inflammatory activity, and one small eczema study found a shea-based cream as acceptable and effective as a ceramide product; there are no large trials.

In cell studies, shea butter extract reduced the inflammatory signals produced by activated immune cells, and a 2017 review of plant oils judged its barrier-repair benefit "possible" rather than proven¹. The main clinical study followed 34 children with eczema using a cream and cleanser containing shea butter extract for four weeks: three-quarters rated it good or very good, itch fell slightly in that group, and the results did not differ from a ceramide-based moisturiser tested earlier². There was no placebo arm. What shea does reliably is what any good occlusive does: slow water loss from dry, cracked skin and soften rough patches. That is useful on elbows, shins, hands and eczema-prone body skin, as part of the approach in eczema and dry, itchy skin, but it does not treat the inflammation underneath.

How people use it

• Warm a small amount between your palms and press it onto damp skin after bathing, to trap water underneath.
• On the body, hands, feet and lips, and as a protective layer over chapped skin in cold weather.
• As an ingredient in moisturisers, typically at 5 to 20%, when raw butter is too heavy.
• Cold-pressed, unrefined butter is extracted without heat or solvents, the method that best preserves a plant oil's beneficial components⁴; refined is a fair choice if you dislike the smell.

Cautions

• It may clog pores on some faces. There is no good trial, but it is a heavy, occlusive fat; if you break out easily, keep it to the body and choose face products labelled non-comedogenic⁵. See oily skin and clogged pores.
• Latex and nut allergy: cross-reaction is a theoretical concern, but laboratory testing found no allergy-provoking proteins in shea butter³. Patch test anyway if you have either allergy.
• Raw butter can go rancid; if it smells sour or sharp, replace it.
• It will not settle weeping, infected or rapidly spreading eczema. See when to see a dermatologist.