From face mist to sunscreen, polyglutamic is the new star acid | Sali Hughes

Just when beauty consumers are finally getting to grips with hyaluronic acid, here comes polyglutamic acid to confuse everyone again. I mention them in the same sentence because at first sight they appear to do the same thing: hold water in skin and, by definition, keep it better hydrated, plumper and looking healthier.

Beauty brands are so excited by encouraging results in consumer and clinical trials of polyglutamic acid (some of which suggest it holds even more water than hyaluronic) that they’re beginning to give it a starring role in their new products.

But before we all drift into a marketeer’s reverie, it is worth noting that although polyglutamic acid is safe, it is not – unlike hyaluronic acid – a substance already naturally present in the body. Independent – which means non-commercial – trials of its benefits are minuscule in quantity compared with those on very established humectants such as glycerin and hyaluronic acid.

Polyglutamic also, at this stage, appears to be a one-trick pony, offering hydration but not yet much else (hyaluronic is also known to calm and soothe, for instance). Which is why, I imagine, the Inkey List has gone for the best of all worlds by including high levels of glycerin in its excellent new Polyglutamic Acid Dewy Sunscreen SPF30 (£14.99).

This is a timely product that will please many. I take issue with the name (it’s less dewy than described and than I’d like, in all honesty) and doesn’t moisturise enough for desiccated me, but this is precisely what makes it a terrific all-rounder for the majority of consumers, who commonly find sunscreens too greasy. Very nicely priced, too.

One of the first brands to harness polyglutamic was Glow Recipe, which uses it with hyaluronic in Watermelon Glow Ultra-Fine Mist (£25), my own warm-weather face spritz of choice. This – if you don’t mind fragrance – does just what a face mist should, instantly reviving, plumping and comforting tired and dehydrated skin in a lasting way. I rarely fly without it.

The other standout user of polyglutamic is REN, in its absolutely brilliant Perfect Canvas Smooth, Prep & Plump Essence (£43). I’ve applied this juicy, soothing liquid before my serum once or twice a day for months – and truly, it made all the difference to my parched skin during a particularly brutal winter on the coast. And since it also contains proven stalwarts hyaluronic acid and glycerin, I’ve no reason to stop now.

Photography Assistant: Bruce Horak