Polyglutamic Acid Best Humectant Hydration Anti-Ageing Polyglutamic Acid at a glance Humectant that provides long-lasting hydration Hydrating efficacy rivals (some studies show it surpasses) hyaluronic acid Made via fermentation of glutamic acid with Bacillus subtilis. May be animal-derived or synthetic Polyglutamic Acid description Polyglutamic acid is a water-soluble humectant capable of attracting and holding water within skin and on its surface. It’s a polymer of the amino acid glutamic acid that’s made via bacterial fermentation using various types of skin-friendly Bacillus, a gram-positive, rod-shaped bacteria. The resulting ingredient has been shown to rival hydrating results of hyaluronic acid; in fact, some studies indicate it surpasses hyaluronic acid, although it does not have that ingredient’s antioxidant or skin-soothing properties, nor is polyglutamic acid naturally found in skin. Although it’s not as well-rounded in the benefits-for-skin department as hyaluronic acid, polyglutamic acid remains a worthwhile ingredient. Just like hyaluronic acid, it’s available in various molecular weights, some capable of penetrating skin’s uppermost layers for multi-level hydration and prevention of water loss that leads to dehydration. Another aspect of polyglutamic acid that it shares with hyaluronic acid is that it forms what’s described as a hydrogel mesh network. This network expands to attract and hold water plus aid delivery of antioxidants (such as quercetin and ferulic acid) to skin that would otherwise prove difficult. Outside the cosmetics industry, polyglutamic acid has gained notoriety for it applications in other fields such as medicine, wastewater treatment, “bio-ink”, and foods. It has replaced or is being studied to replace various other ingredients that are not biodegradable, making polyglutamic acid an environmentally friendly option. Standard usage levels in cosmetics range from 0.05%–1%.