Shea butter is an emollient and humectant, which means it soothes and softens skin, while at the same time reducing moisture loss. Proponents of shea butter claim it can reduce the visibility of wrinkles and blemishes; prevent stretch marks during pregnancy; and treat dry and peeling skin, frostbite, insect bites, sunburn, muscle aches, poison ivy and oak rashes, eczema, dermatitis, and burns.
Clinical research has not yet validated the numerous claims about shea butter's positive effects on skin and hair, though many people report improved skin and hair health when using shea butter products. Cell and animal studies suggest shea butter may have antioxidant, anti-inflammatory, and anticancer abilities, though these effects have not been proven in human clinical trials.
Shea butter should be used with caution in terms of applying directly on broken skin or on skin areas affected by infections, psoriasis, or other serious skin conditions. Some shea butter products have added fragrances and other ingredients, and these may irritate sensitive skin; test on a small area of your skin before using on larger areas. Opt for a fair trade product if you have concerns about how shea butter is produced, or about how the shea butter producers are treated and paid for their work.
(Akihisa T, Kojima N, Kikuchi T, et al. Anti-inflammatory and chemopreventive effects of triterpene cinnamates and acetates from shea fat. J Oleo Sci. 2010;59:273-80.)
(Zhang J, Kurita M, Shinozaki T, et al. Triterpene glycosides and other polar constituents of shea (Vitellaria paradoxa) kernels and their bioactivities. Phytochemistry. 2014;108:157-70.)