Threonine
Essential amino acid. Part of NMF, supports hydration and barrier.
Evidence by route
Topical application
Safe NMF amino acid.
How to read tiers A–F
- BLimited evidence. One RCT or several controlled studies with limitations
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Normal, Dry, Oily, Combination, Sensitive
About this ingredient
Threonine (L-Threonine) is an essential amino acid. In skin – a component of proteins and part of the natural moisturizing factor (NMF). Mechanism. In the stratum corneum, NMF amino acids (including threonine, serine, alanine) retain water and support elasticity. Topically, in amino-acid complexes, threonine integrates into upper layers and acts as a mild humectant. Where applied. Serums and creams with amino-acid complexes, k-beauty products, repair masks. Final-product concentration rarely above 0.5%. Evidence base. Standalone topical-threonine RCTs are scarce. Most data are on NMF amino-acid complexes combined with hyaluronic acid and ceramides – synergistic hydration effect (Choi 2014). Safety. CIR confirmed safety. Hypoallergenic, non-comedogenic. No systemic absorption. Pregnancy and lactation – safe.
Frequently asked questions
Is Threonine safe during pregnancy?
Threonine is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Threonine for?
Threonine suits: normal, dry, oily, combination, sensitive.
What is Threonine and what does it do in cosmetics?
Essential amino acid.
What's the INCI name for Threonine?
The INCI name is Threonine. It may also appear as: L-Threonine.
See Threonine in a product composition right on the store page
The Evigrade extension adds an evidence panel to iHerb, Sephora, Druni 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.
Similar role in the formula
Explore by category
Published: · updated: