What it is
Threonine is one of the standard protein-building amino acids and is among the components found in the skin's natural moisturizing factor. In formulations it serves as a water-soluble conditioning agent and humectant that helps attract and hold moisture at the skin surface. It is often included as part of amino-acid blends intended to support a soft, conditioned feel.
Safety & warnings
Threonine is a naturally occurring amino acid and is generally regarded as well tolerated, non-irritating, and non-sensitizing at the levels used in cosmetics. It is not associated with comedogenicity.
Origin & sourcing
Typically produced by fermentation or synthesis; it is a naturally occurring amino acid found in proteins.
Questions everyone asks
What is threonine used for in skin care?
It is a skin-conditioning amino acid and humectant that helps the skin surface hold moisture and feel soft.
Is threonine irritating?
It is a naturally occurring amino acid and is generally considered gentle and well tolerated in cosmetic use.