What it is
Hydroxyectoin is the hydroxyl-bearing analog of ectoine, a small zwitterionic osmolyte that extremophilic microorganisms accumulate to stabilize water and proteins under stress. In cosmetics it is used as a humectant and skin-conditioning agent that helps bind water and support the skin barrier. In sunscreens it is included as a soothing, moisture-supporting additive rather than a UV filter.
Safety & warnings
Hydroxyectoin is generally very well tolerated, with low irritation and sensitization potential, and is not considered comedogenic.
Origin & sourcing
Produced by microbial fermentation; it is the hydroxylated derivative of ectoine, an osmolyte made by certain bacteria.
Questions everyone asks
What is hydroxyectoin?
It is a hydroxylated form of ectoine, a small protective osmolyte that microorganisms use to stabilize water and proteins.
What does it do in skincare?
It acts as a humectant and conditioning agent, helping skin hold water and supporting the barrier.