THREONINE

📋 Quick facts

Description: THREONINE — amino acid, part of the skin natural moisturizing factor (NMF).

All Functions: amino acid, part of the skin natural moisturizing factor (NMF)

Quick Facts:

• Category: humectant

Proven Benefits At A Glance:

• L-threonine is an essential amino acid used in food, cosmetics, pharmaceuticals, and animal feed
• Your body cannot make threonine—it must come from diet or supplements
• Current research focuses on producing threonine efficiently through fermentation rather than chemical synthesis
• The available research does not establish specific skincare benefits of threonine as a topical ingredient

⚗️ Chemical Overview

2-amino-3-hydroxybutanoic acid is an alpha-amino acid that is butanoic acid substituted by an amino group at position 2 and a hydroxy group at position 3. It has a role as a plant metabolite. 2-amino-3-hydroxybutanoic acid has been reported in Escherichia coli, Bulbophyllum echinolabium, and other organisms with data available. Threonine is an essential amino acid in humans. It is abundant in human plasma, particularly in newborns. Severe deficiency of threonine causes neurological dysfunction and lameness in experimental animals. Threonine is an immunostimulant which promotes the growth of thymus gland. It also can probably promote cell immune defense function. This amino acid has been useful in the treatment of genetic spasticity disorders and multiple sclerosis at a dose of 1 gram daily. It is highly concentrated in meat products, cottage cheese and wheat germ. The threonine content of most of the infant formulas currently on the market is approximately 20% higher than the threonine concentration in human milk. Due to this high threonine content the plasma threonine concentrations are up to twice as high in premature infants fed these formulas than in infants fed human milk. The whey proteins which are used for infant formulas are sweet whey proteins. Sweet whey results from cheese production. Threonine catabolism in mammals appears to be due primarily (70-80%) to the activity of threonine dehydrogenase (EC 1.1.1.103) that oxidizes threonine to 2-amino-3-oxobutyrate, which forms glycine and acetyl CoA, whereas threonine dehydratase (EC 4.2.1.16) that catabolizes threonine into 2-oxobutyrate and ammonia, is significantly less active. Increasing the threonine plasma concentrations leads to accumulation of threonine and glycine in the brain. Such accumulation affects the neurotransmitter balance which may have consequences for the brain development during early postnatal life. Thus, excessive threonine intake during infant feeding should be avoided. (A3450).

Source(s): LOTUS – the natural products occurrence database, ChEBI, Toxin and Toxin Target Database (T3DB), via PubChem

📊 Comedogenicity

🛡️ Safety rating

Safety tier is a starting heuristic from regulatory status and comedogenic rating, not a dermatological verdict — see our Terms for the full disclaimer. Research confidence reflects how many real cited studies back this ingredient, not the strength of their findings.

🌍 Regulatory Status

💧 Skin Type Compatibility

⚠️ Don’t Combine With

📚 Research & Evidence

🔬 The Science

L-threonine is classified as one of the three major essential amino acids, meaning your body cannot synthesize it and must obtain it from external sources (J Agric Food Chem, 2025; Metab Eng, 2025). It has broad applications across food, pharmaceuticals, cosmetic products, and animal feed industries (J Agric Food Chem, 2025). Currently, the industrial production of L-threonine has evolved into an efficient, cost-effective, and environmentally friendly process based on fermentation using microorganisms like Escherichia coli and Corynebacterium glutamicum rather than chemical synthesis (Metab Eng, 2025). This means threonine in skincare products is likely produced through sustainable microbial fermentation. The research abstracts provided focus heavily on the biochemistry of threonine production and industrial scaling, as well as unrelated cellular signaling mechanisms.

However, they do not contain specific claims about threonine’s effects on skin health, barrier function, hydration, or any other dermatological benefit. The sources discuss threonine’s role in various industries but do not establish evidence for particular skincare applications when used topically or as an ingredient in cosmetic formulations.

📄 Related Research

Matched by search — not necessarily verified support for every statement above.

• Fang Y et al. (2021). Tribbles homolog 2 (Trib2), a pseudo serine/threonine kinase in tumorigenesis and stem cell fate decisions. Cell Commun Signal.
• Nie Y et al. (2025). Microbial Production of l-Threonine Using Metabolically Engineered Escherichia coli. J Agric Food Chem.
• Zhao G et al. (2025). Recent advances on engineering Escherichia coli and Corynebacterium glutamicum for efficient production of L-threonine and its derivatives. Metab Eng.
• Hao R et al. (2023). Dynamic and balanced regulation of the thrABC operon gene for efficient synthesis of L-threonine. Front Bioeng Biotechnol.
• Nagao M et al. (1995). Protein serine/threonine phosphatases as binding proteins for okadaic acid. Mutat Res.

🧴 Products Containing THREONINE

• L’OREAL NORGE AS L’Oreal Lash Serum Transparent
• BCL Kansosan Skincare Moisture Base AQ
• RETINOL RETINOL SKIN CREAM
• MyProtein Hair & body wash
• L’OREAL NORGE AS Excellence 10 Ekstra Lys Blond
• L’OREAL NORGE AS Excellence 5.5 Lys Mahognibrun
• L’OREAL NORGE AS Excellence 9 Meget Lys Blond
• L’OREAL NORGE AS Excellence 6 MørkeBlond
• Nacomï White Black Face Mask
• Bioélixire Odżywka do włosów zniszczonych
• L’OREAL NORGE AS Excellence 8.3 Lys Gyldenblond
• Tío Nacho Tío Nacho Anti-Caida Engrosador
• L’OREAL NORGE AS Excellence 4.3 Golden Brown
• L’OREAL NORGE AS Excellence Creme Ultra 3.11 Ash Dark Brown
• L’OREAL NORGE AS Excellence Creme Ultra 4.11 Ash Brown
• HEMA Long Lasting Nail Polish 358 Pink Peony
• Eucerin Eucerin, Roughness Relief Lotion, Fragrance Free
• Eucerin
• marc anthony argan shampoo
• Pacifica Cosmic Hemp Balancing Face Wash
• NIOD Multi-Molecular Hyaluronic Complex (MMHC2)
• The Ordinary The Ordinary Glycolic Acid 7% Toning Solution (Solução tonificante de ácido glicólico 7%)
• ordinary suncream
• dr groot shampoo
• Clover Smoothing Deep Conditioner
• Paul Mitchell Paul Mitchell Awapuhi Shampoo
• collagen face mask
• OPLAPLEX Leave In – Numéro 5
• Sephora Beauty insider
• Olaplex No. 8 Bond Intense Moisture Mask
• FILORGA TIME-FILLER Crème Absolue Correction Rides
• CeraVe Hydrating cream-to-foam cleanser
• Filorga Filorga Hydra Filler 50ML
• L’OREAL NORGE AS Excellence Creme Ultra 5.11 Ash Light Brown
• L’OREAL NORGE AS Excellence Creme Ultra 7.11 Ash Blond
• CeraVe Hyrdrating Cream To Foam Cleanser
• Coop Italia Crema viso Anti Rughe Intensiva Notte
• Davines Davines MOMO Moisturizing Shampoo
• Eucerin Urea Repair
• Papoutsanis KARAVAKI