Essential amino acid, isomer of leucine. In skincare – part of NMF amino acid cocktails, without a standalone claim. In keratinocyte studies isoleucine stimulates synthesis of beta-defensin-2, an antimicrobial peptide – but the clinical significance of this effect with topical application is not proven.
Topical application
CWeak evidence. In vitro data, open-label studies, or expert consensus.
Safe component of amino acid complexes. Promising in vitro data on innate immunity stimulation have not yet been confirmed clinically.
Isoleucine is an essential branched-chain amino acid, structural isomer of leucine. Enters the body only with food. Component of muscle proteins and neuropeptides. Where applied. Part of amino acid blends in NMF (Natural Moisturizing Factor) of creams, serums, toners (0.01-0.5%). In Spain in Sesderma Factor G, Filorga NCEF, Mesoestetic. Evidence base. On keratinocytes in vitro isoleucine stimulates synthesis of beta-defensin-2 – an antimicrobial peptide (Fehlbaum 2000, Schauber 2004). Potentially useful in atopic dermatitis and acne, but clinical significance with topical use is not proven. No direct RCTs on topical isoleucine. Safety. CIR rated isoleucine and other amino acids safe at cosmetic concentrations (2013). Inert, hypoallergenic. Pregnancy and lactation – safe topically. Suitable for all skin types.
Irritation potential
LowAllergen risk
LowPregnancy
SafeSuitable for
The Evigrade extension adds an evidence panel to Wildberries, Goldapple, Letu, iHerb, Sephora and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
Isoleucine is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
Isoleucine suits: normal, dry, combination, oily, sensitive.
Essential amino acid, isomer of leucine.
The INCI name is Isoleucine. It may also appear as: L-Isoleucine, Изолейцин.
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