What is it?
A small, water-binding molecule that salt-tolerant bacteria make to protect their cells from salt, drought, heat and other stresses. For commercial use, ectoine is produced by growing such bacteria, mainly Halomonas elongata, and purifying what they make. In skin care it is used as a skin-conditioning, moisture-binding ingredient, and it is also found in some nasal sprays, eye drops and creams sold for dry or irritated skin and mucous membranes.
Key information
- Ectoine is made naturally by salt-tolerant bacteria to protect their cells, and is produced commercially by bacterial fermentation.
- The EU inventory lists ectoin as a skin-conditioning ingredient, with no restrictions or opinions from its Scientific Committee on Consumer Safety.
- In a 2014 double-blind trial in 65 adults with mild to moderate eczema, an ectoine cream was very well tolerated.
More information
Ectoine was first discovered in the salt-loving bacterium Ectothiorhodospira halochloris, and several other bacteria that live in salty, dry or otherwise harsh conditions make it too. It binds water tightly and forms a protective hydration shield around proteins and other biomolecules, which helps cells survive stress. Industrial production relies mainly on Halomonas elongata, a salt-tolerant bacterium that stores ectoine as its main protective solute.
The EU’s cosmetic ingredient inventory (CosIng) lists ectoin as a skin-conditioning agent, with no restrictions and no opinions from the EU’s Scientific Committee on Consumer Safety. A 2024 scientific review describes ectoine as having “an excellent tolerability and safety profile,” while noting that clinical trials are still limited. In a 2014 randomized, double-blind trial, 65 adults with mild to moderate atopic dermatitis applied an ectoine cream twice a day for 28 days, and the researchers reported that it was very well tolerated.
Ectoine has a shorter track record in cosmetics than most ingredients in this database, and the published data come mainly from clinical and laboratory studies rather than a formal expert-panel ingredient review. What is available points to good tolerability on skin and mucous membranes. On ingredient lists it appears as ectoin, the INCI spelling; ectoine is the spelling used in most scientific papers.
Sources: European Commission CosIng: Ectoin; Pharmaceutics (2024): Ectoine, from a natural bacteria protectant to a new treatment of dry eye disease; Microbial Cell Factories (2024): Temporal dynamics of stress response in Halomonas elongata to NaCl shock; Skin Pharmacology and Physiology (2014): Ectoine-containing cream in the treatment of mild to moderate atopic dermatitis, a randomised double-blind trial
