All products are independently selected by our editors. If you buy something, we may earn an affiliate commission.

For the past year, the best ectoin skin-care products have been all the hype in the beauty world -- and for good reason. This amino acid is an extremolyte, meaning it protects cells in extreme conditions like harsh temperatures and environments. Originally discovered in bacteria that thrive in salt lakes, ectoin helps shield these organisms' cells from damage. On skin, it does the same thing -- forming a barrier against UV damage, pollution, and free radicals. Ectoin helps your skin cells fight and heal damage from environmental stressors, says board-certified dermatologist Karan Lal, MD.

But ectoin isn't just about protection -- it's a skin-care multitasker. It's also especially beneficial for dry, irritated skin, including those dealing with retinoid irritation or conditions like eczema. By hydrating and strengthening the skin barrier, it prevents moisture loss and calms irritation. Studies also show that it can reduce redness and inflammation, making it a safe option for all skin types. Whether you're looking to soothe dryness from retinol, repair a compromised barrier, or simply keep your skin protected, ectoin is an ingredient worth adding to your routine. Here, we tapped dermatologists and scanned the market for the best ectoin products, below.

Why we love it: Ectoin is a powerful skin protectant and humectant, but when paired with other hydrators, it becomes, as board-certified dermatologist Pooja Rambhia, MD, puts it, "a hydration powerhouse." She explains that by combining ectoin with a high-molecular-weight amino acid like polyglutamic acid, along with barrier-supporting glycerin, the formula helps lock in deep, long-lasting moisture. The Multi-Quench Plumping Hydration Serum from Prequel does exactly that -- all in one super-gentle, lightweight formula.

Editor's tip: Although the science is still out, polyglutamic acid is said to outperform hyaluronic acid in hydration, holding 4,000-5,000 times its weight in water compared to hyaluronic acid's 1,000 times.