Quick answer

An essential amino acid that provides hydrating benefits; Plays a role in maintaining collagen and elastin (when consumed); Works with other amino acids to maintain skin’s barrier; May be animal-derived or synthetic Key benefits: Hydration.

Isoleucine

Updated

L-Isoleucine; DL-allo-Isoleucine; 2-Amino-3-methylpentanoic acid

Purpose

Amino acid that whose humectant properties help maintain skin’s hydration while consuming isoleucine via foods supports skin’s collagen and elastin.

Rating

GOOD

Category

Humectant

INCI Purpose

ANTISTATIC, HAIR CONDITIONING, SKIN CONDITIONING

Benefits

Hydration — Attracts and locks in moisture to keep skin plump and dewy

Alternative Names

At a Glance

An essential amino acid that provides hydrating benefits

Plays a role in maintaining collagen and elastin (when consumed)

Works with other amino acids to maintain skin’s barrier

May be animal-derived or synthetic

Article

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 (Paula’s Choice uses the latter) 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.

See: Amino Acids

References