Trehalose

Trehalose is a sugar made of two glucose units that some organisms use to survive almost complete drying out. In skincare it is used as a humectant, an ingredient that attracts and holds water, and as a stabilizer.

At a glance

• Evidence level A. Published research on the ingredient itself.
• What it is. A non-reducing disaccharide found in yeast, fungi, insects and some desert plants.
• What it does. Holds water. Skin feels hydrated and smooth.
• Caution. Very well tolerated. Its safety record includes long use as a food ingredient.

What it is

Trehalose joins two glucose molecules in a way that makes it unusually stable. It does not react readily with proteins and it resists breakdown by heat and acid better than most sugars.

Because it is a non-reducing sugar, trehalose does not take part readily in the browning reactions that other sugars undergo with proteins and amino acids. That chemical quietness is one reason it is used to protect sensitive materials in food and pharmaceutical products.

It is best known from anhydrobiosis, the ability of some organisms to lose nearly all their water and revive when water returns. Brewer's yeast, tardigrades and the "resurrection plant" all accumulate trehalose as they dry. Commercial trehalose is produced enzymatically from starch.

What it does in skincare

As a humectant, trehalose binds water in the upper layers of skin and gives a smooth, non-greasy feel. It is usually one of several humectants in a formula, because each binds water differently and a blend feels better than a high dose of one.

Formulators also value trehalose as a stabilizer. The same property that protects proteins in a drying cell helps keep sensitive ingredients intact in a formula. Protecting actives from breakdown is a formulation question with its own page: stability and protection.

A humectant draws water; a moisturizer seals it in. Follow a humectant serum with a moisturizer. More on routines: hydration and barrier.

Evidence

The studies below describe the ingredient itself.

Crowe and colleagues showed in 1984 that trehalose preserves the structure of biological membranes during drying, work that explained how anhydrobiotic organisms survive. Elbein and colleagues reviewed trehalose's many biological roles in 2003.

In pharmaceutical science, Ohtake and Wang reviewed trehalose as a stabilizer for proteins and other biological products during freeze-drying and storage. Richards and colleagues reviewed its properties, history of use and a series of safety studies in support of its use in food.

Most of this evidence is biology, food science and pharmaceutical formulation. It explains why trehalose holds water and protects fragile molecules. The skin-specific clinical literature on trehalose as a single cosmetic ingredient is limited.

Use and caution

• Trehalose is rarely associated with irritation and suits most skin types.
• Apply humectant serums to slightly damp skin, then follow with a moisturizer.
• As with any new product, patch test first if your skin is reactive.

In Vegalab products

The Hydrating NanoSerum sealed vial set lists trehalose among its water-binding ingredients, with sodium PCA, betaine, glycereth-26, butylene glycol and ectoin.

• Hydrating NanoSerum, Sealed Vial Set

Reading a humectant group in a full declaration: how to read an ingredient list.

Related ingredients

• Betaine, an osmolyte humectant
• Sodium PCA, a component of skin's natural moisturizing factor
• Ectoin, another molecule organisms use to survive stress
• All entries: ingredient library

References

1. Crowe JH, Crowe LM, Chapman D. Preservation of membranes in anhydrobiotic organisms: the role of trehalose. Science. 1984;223(4637):701-703.
2. Elbein AD, Pan YT, Pastuszak I, Carroll D. New insights on trehalose: a multifunctional molecule. Glycobiology. 2003;13(4):17R-27R.
3. Ohtake S, Wang YJ. Trehalose: current use and future applications. J Pharm Sci. 2011;100(6):2020-2053.
4. Richards AB, Krakowka S, Dexter LB, et al. Trehalose: a review of properties, history of use and human tolerance, and results of multiple safety studies. Food Chem Toxicol. 2002;40(7):871-898.