For your skin
A rich, naturally occlusive plant butter from the African karite tree. Calms eczema-prone skin, refills the lipid barrier, and (in randomized trials) is acceptable and effective enough that three quarters of pediatric AD patients use it as a steroid-sparing emollient.
Want the science? Keep reading ↓Mechanism of action
Saponifiable fraction (oleic and stearic acids) restores stratum corneum lipids; the unsaponifiable fraction (triterpene alcohols, cinnamate esters, tocopherols) suppresses NF-kB activation, dampening inflammatory cytokine release in keratinocytes.
Why we tier this moderate
3 cited papers across 2 countries. The mechanism is well-described and there's at least one controlled trial in the literature, but we tier this Moderate rather than Strong to stay honest about how many specific papers we cite directly.
Cited research
Burnett CL, Bergfeld WF, Belsito DV, et al. Safety Assessment of Butyrospermum parkii (Shea)-Derived Ingredients as Used in Cosmetics. Cosmetic Ingredient Review Expert Panel Final Report.
Verallo-Rowell VM, Katalbas SS, Pangasinan JP. Natural (Mineral, Vegetable, Coconut, Essential) Oils and Contact Dermatitis. Curr Allergy Asthma Rep. 2016;16(7):51. — discussing shea butter unsaponifiable fraction NF-kB inhibition and dermatologic use.
Hon KL, Tsang YC, Pong NH, et al. Patient acceptability, efficacy, and skin biophysiology of a cream and cleanser containing lipid complex with shea butter extract versus a ceramide product for eczema. Hong Kong Med J. 2015;21(5):417-425.
Sources: PubMed · KCI · J-Stage · CNKI · Wanfang · SFD · MFDS · Cochrane · SCCS · CIR. Every entry points to a specific document. See methodology for what each outcome label means.