What is shea butter and why does it work?
Shea butter is a fat extracted from the nut of the African shea tree (Vitellaria paradoxa), native to the shea belt stretching from West to East Africa. It contains an unusually high proportion of unsaponifiable fats (7β12%) compared to other plant butters β these are the biologically active fractions that cannot be converted to soap and are responsible for most of its skin benefits. The key unsaponifiables include cinnamic acid esters (anti-inflammatory, UV-screening), lupeol and butyrospermum parkii (wound-healing), and tocopherols (vitamin E, antioxidant). The fatty acid profile β approximately 45% stearic acid and 43% oleic acid β creates the characteristic solid-at-room-temperature texture and explains its occlusive, deeply moisturising properties.
Grade A vs Grade C shea butter: what the difference means
Shea butter is graded A through F based on extraction method and refinement level. Grade A (raw/unrefined): extracted using cold-water method, minimally processed, retains full complement of vitamins, cinnamic acid, and active compounds. Colour ranges from ivory to yellow-green depending on origin. Has a natural nutty scent. Grade B (refined): chemically extracted using hexane solvents and then deodorised β removes most bioactive compounds. White, odourless. Grade C and below: highly refined, mixed with preservatives or other ingredients. For skincare purposes, always choose Grade A unrefined shea butter. The refined versions are cheaper and have a longer shelf life but lose the anti-inflammatory cinnamic acid and much of the tocopherol content that make shea butter effective.
Proven skin benefits of shea butter
A 2010 study in the Journal of Oleo Science found that shea butter's cinnamic acid content provides sun protection equivalent to approximately SPF 6 β not sufficient as a standalone sunscreen, but meaningful as a base layer. Multiple in-vitro studies have confirmed its anti-inflammatory activity, specifically its inhibition of TNF-alpha and NF-ΞΊB, the same inflammatory pathways implicated in eczema and atopic dermatitis. A 2019 meta-analysis in the Dermatitis journal found shea butter-based preparations significantly improved skin hydration and reduced trans-epidermal water loss (TEWL) compared to placebo in patients with mild-to-moderate atopic dermatitis. It also demonstrates wound-healing properties: a 2017 study found shea butter promoted fibroblast proliferation and collagen synthesis in skin cell cultures.
Building a body care routine with shea butter
The most effective way to use shea butter for body moisturisation is the 'seal while damp' technique: shower or bathe, pat skin dry leaving slight moisture on the surface, then apply shea butter within 3 minutes. The remaining moisture provides the humectant layer while shea butter's occlusive properties seal it in. For very dry or eczema-prone skin: apply a thin layer of glycerin (diluted to 10% in water) first as a humectant, then seal with shea butter. For oily skin on the body: mix shea butter with a lighter carrier oil such as argan or jojoba in a 1:2 ratio. For hyperpigmented patches on arms or legs: combine raw shea butter with kojic acid lotion, applying shea butter over the top to seal in the active ingredient.
Shea butter for stretch marks, scars, and keloidal skin
Shea butter is frequently used for stretch mark prevention during pregnancy and for scar management. The evidence for stretch mark prevention is mixed: a 2016 review in the British Journal of General Practice found shea butter-based preparations did not statistically outperform placebo for stretch mark prevention in pregnancy. However, for existing stretch marks and scars, shea butter's combination of cinnamic acid (anti-inflammatory), lupeol (wound healing), and stearic/oleic fatty acids does improve skin suppleness and visibly reduces the texture contrast of raised scars over time. For keloidal skin (raised, hypertrophic scars common in melanin-rich skin types), consistent daily application improves softness but should be combined with silicone-based scar sheets for optimal results.