Encyclopedia · chelator
Tetrasodium glutamate diacetate
A biodegradable, glutamic-acid-based chelator marketed as a greener EDTA replacement, with essentially no hair-specific data.
What it is
GLDA is made from glutamic acid, often from fermentation, and is used in natural and sulfate-free shampoos to bind hardness ions and improve preservative performance.
How it works
It binds calcium, magnesium, iron and copper like EDTA. Our PubMed search returned only agricultural, environmental and animal-feed GLDA papers and no cosmetic or hair study.
What the studies show
We found no cosmetic, hair or scalp study. The rationale rests on chemistry and manufacturer claims. A general review of shampoo surfactant technology covers the wider trend toward sulfate-free and greener systems but is not about GLDA itself (Cornwell 2018).
Side effects and safety
We found no safety concerns, but also limited independent dermatological data.
Bottom line
A reasonable sign in a mild or eco-minded shampoo, not a proven hair benefit. Whether it matches EDTA's performance on hair deposits is untested in public data.
Studies 1
Cornwell PA. A review of shampoo surfactant technology: consumer benefits, raw materials and recent developments. Int J Cosmet Sci. 2018
Result: Overview of shampoo surfactant raw materials, consumer benefits and trends in sulfate-free systems.
Read the study ↗Related
- Disodium EDTAThe classic cosmetic chelator, which grabs calcium, magnesium, iron and copper so shampoos lather and keep in hard water, with no clinical hair trials of its own.
- Tetrasodium EDTAThe more alkaline, more soluble EDTA salt, with the same chelating job as disodium EDTA and wide use in clarifying and chelating shampoos.
- Sodium phytateA rice- or corn-derived chelator used in natural shampoos as a preservative booster and iron and copper binder, with no hair trials.
- Citric acidThe most common pH adjuster in shampoos and conditioners and, in a 2025 lab study, a calcium-removing treatment that strengthened chemically treated hair.