Isoleucine
Reviewed by Daisy · Last updated 18 Aug 2026
Also known as: Amino Acids
An essential amino acid that provides hydrating benefits | Plays a role in maintaining collagen and elastin (when consumed)
Addresses
EWG Safety Score
Isoleucine products at Skintique
View all →
What Is Isoleucine?
Isoleucine is an essential amino acid that has slight humectant (water-binding) properties for skin. It’s considered essential since the human body cannot make isoleucine and so it must be obtained via foods or supplements.
Isoleucine works with other amino acids to help maintain skin’s barrier and initiate surface repair so skin looks healthier. It is often combined with several amino acids for enhanced benefits.
This amino acid may be animal-derived or synthetic and its typical concentration in skin care ranges from 0.0003–0.002%, as very little of this ingredient is needed in order for skin to benefit.
Clinical Evidence & References
Published Research
-
Molecules, August 2021, pages 1–43 [https://www.mdpi.com/1420-3049/26/1/43]
-
International Journal of Toxicology, November-December 2013, pages 41S–64S [https://journals.sagepub.com/doi/10.1177/1091581813507090]
-
Amino Acids, April 2012, pages 2,481–2,489 [https://link.springer.com/article/10.1007/s00726-011-1059-z]
From the Clinic
Not sure what your skin actually needs?
Two minutes, a few questions, and we’ll point you at what matters — no guesswork.
Take the skin quizRelated Ingredients
Hydroxypropyl Tetrahydropyrantriol
Derived from xylose (a sugar abundant in beech trees) | Used in skin care products for its purported anti-ageing and hydrating properties
Hypericum Perforatum Extract
A plant extract with traditional skin-comforting roots and emerging research support
Iron Picolinate
An iron-binding compound with potential antioxidant properties for photoprotection
Jasminum Officinale Flower/Leaf Extract
A floral extract that conditions the skin and adds subtle fragrance
Jasminum Officinale Oil
A fragrant botanical oil that conditions skin and adds sensory richness to formulations
Leonurus Sibiricus Flower … Stem Extract
A botanical extract traditionally used to calm and soothe reactive skin
Learn More About Skincare Ingredients
Explore our comprehensive ingredient glossary to understand what's in your products.
Browse All IngredientsShop Our Products
Find professional skincare solutions at Skintique.