The research behind our Smoothing Eye Cream

Horse chestnut, escin, hyaluronic acid and the rest: what each ingredient does around the eyes, the studies behind it, and what those studies can't tell you.

Every ingredient discussed here is in the eye cream. The studies tested ingredients at stated strengths, usually in other products, and we say so each time.

Eye creams are some of the most over-promised products in skincare. "Erases dark circles", "eliminates puffiness", "lifts in seconds". Most of those claims rest on very little. The skin around your eyes deserves better than that, and so does your money.

This guide goes through our Smoothing Eye Cream one ingredient at a time: what was tested, on whom, what was found, and what it doesn't prove. If you only want the product, the eye cream page has everything in one place.

01Why eye skin needs its own cream

The skin around your eyes is among the thinnest on your body. It has fewer oil glands than your cheeks, so it dries out faster, and it moves thousands of times a day every time you blink, smile or squint. That's why fine lines and a creased, tired look tend to show there first.

It is also more reactive. Ingredients your cheeks handle happily, such as strong retinoids or acids, often sting around the eyes. And because the area is so small and delicate, heavy, rich creams can feel greasy and sit on the surface rather than sinking in.

A good eye cream is a balance: enough hydration and comfort to make a visible difference, in a texture light enough to use twice a day, under makeup, without irritation. That balance is what we designed our Smoothing Eye Cream around.

02What actually helps: an honest overview

We built the formula to be strong where eye creams genuinely work, hydration and a smoother look, and honest where they don't. If deep lines are your main concern and your skin tolerates it, retinol still has the most evidence; our retinol guide explains when it's worth it.

03How we rate the evidence

None of these studies tested our eye cream. This formula doesn't have its own consumer testing yet, so we don't show results for it.

04Horse chestnut extract

Horse chestnuts are the shiny brown seeds of Aesculus hippocastanum, the tree children know for conkers. The seed extract has a long history in European herbal practice for tired, heavy legs, and it's widely used in skincare today.

05Escin

Escin (also spelled aescin) is a mix of saponins, the best-known active compounds in horse chestnut seeds. Taken by mouth, horse chestnut extract standardised to escin is used for chronic venous insufficiency, and escin gels are sold in some countries for bruises and swelling.

So why include it? Because it's a well-characterised compound from the same plant, and it complements the extract. We just won't tell you it drains puffiness. We haven't tested that and neither, as far as we can find, has anyone else, not in a cosmetic eye cream.

06Hyaluronic acid, aloe and glycerin

If there's one thing an eye cream can do reliably, it's hydrate. Well-hydrated skin reflects light more evenly and fine, dry lines soften. These three ingredients have the best human evidence in the formula.

This study is unusually relevant: it was done around the eye, which is exactly where you'll use this cream.

Aloe is the first ingredient, so it's the largest single part of the formula. In a two-week study of 20 women (Dal'Belo et al., 2006), creams with freeze-dried aloe increased the water content of the skin's outer layer. It was a small forearm study and says nothing about lines.

Glycerin, third on the list and made using organic ingredients, is one of the most effective humectants there is. A 2008 review in the British Journal of Dermatology (Fluhr, Darlenski and Surber) summarised decades of research showing it improves hydration and barrier function and helps protect against irritation.

We've written about these three in more depth in the research behind our serum.

07Sodium PCA

PCA is the largest single component of the skin's own natural moisturising factor, the mix of small molecules that holds water in the outer layer. Sodium PCA is its salt. A 1981 review by Clar and Fourtanier reported that creams with at least 2% PCA or PCA salt improved dry skin in short and long-term use. It is an older review, much of it the authors' own work, and we don't know the percentage in our formula, where it sits ninth on the list.

There's more detail in the research behind our moisturiser.

08Dipalmitoyl hydroxyproline

Hydroxyproline is an amino acid found in the skin's supporting structure. Joining it to two chains of palmitic acid makes it oil-soluble, and it sits eighth in our formula. Its maker reports firmer-looking skin and a large reduction in visible wrinkles against placebo, but hasn't published the study details. We found no independent, peer-reviewed human trial, so we list it as supporting, and promising rather than proven.

09Plant lipids, jojoba and shea

Your skin barrier is held together by lipids, including ceramides. Our formula contains glycosphingolipids and glycolipids, plant lipids related to the ceramides in skin, alongside organic jojoba oil and shea butter. Together they give the cream its comfort and help reduce the feeling of tightness around the eyes.

We'll be precise about the evidence. Jojoba has supporting research as a skin-friendly liquid wax (Pazyar et al., 2013, a review). Shea butter is a long-used emollient. We found no trial of these specific plant lipids applied around the eye, so we describe what they are and don't claim more.

10Black tea extract

Tea leaves are rich in polyphenols, antioxidants that show protective activity in lab studies. Tea extracts are popular in eye products, often with claims about puffiness. We found no human trial of black tea extract around the eyes, so we list it as a supporting antioxidant, along with the small amounts of vitamin E (tocopherol) and vitamin C (ascorbyl palmitate) that help keep the formula fresh.

11Puffiness and dark circles: what an eye cream can't do

Morning puffiness usually comes from fluid collecting under the thin skin around the eyes overnight. Salt, alcohol, allergies, crying, lying flat and simple genetics all play a part. It tends to ease as you move around during the day. A cool eye cream can feel refreshing, and some ingredients may help a little, but no cosmetic cream removes puffiness, and we don't claim ours does.

Dark circles have several causes: pigment in the skin, blood vessels showing through thin skin, and shadows from the shape of the eye area. Hydration can make the area look fresher, but most dark circles respond better to good sleep, SPF, treating allergies and, frankly, concealer.

12How to choose an eye cream

13How to use it

Tap the cream gently along the bone around each eye with your ring finger, the finger with the lightest touch. Keep away from the lids and lash line; the cream will spread a little on its own. If you use our Retinol Alternative Eye Serum, apply it first, then the eye cream. Follow with our Retinol Alternative Moisturiser or your own.

Used morning and evening, a 15 ml bottle lasts around two to three months. Give it eight to twelve weeks before judging it on fine lines.

14Who it suits

It suits you if your eyes look tired, dry or slightly creased by the end of the day; you want a light eye cream for morning and evening that sits well under makeup; retinol eye creams sting or dry you out; or you want every ingredient named before you buy.

Skip it, or check first, if you need a fragrance-free eye product; your eyes are suddenly swollen, itchy or red; you react to horse chestnut; you're pregnant or breastfeeding and haven't asked your doctor; or you want retinol-level results on deep lines.

15What it adds up to

This is an eye cream built on the evidence that exists for eye creams: strong for hydration, promising for horse chestnut, and honest about puffiness and dark circles. The hyaluronic acid evidence was gathered around the eye itself, and so was the horse chestnut study, which is more than most eye creams can say.

If you want a light, gentle, twice-daily eye cream with every ingredient on show, this is the one we'd point you to. If deep lines are your priority and your skin can take it, look at retinol; if you'd prefer a serum texture with a retinol alternative, our eye cream or eye serum guide will help you choose.

16Your questions, answered

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