I have always had dark under-eye circles. When I was younger, I attributed it to long nights studying during law school or late night outs gossiping with my roommates. But over time, these pesky offenders persisted. The truth is, under-eye bags are caused by various factors, and lack of sleep is only one of the primary culprits. Yes, studies show that when we don’t get enough rest, the blood vessels under our eyes dilate, resulting in dark circles and puffiness. But other research has shown that stress is another significant contributor because high stress levels can lead to increased inflammation. What’s more, under-eye bags can be genetic.

L’Oréal Paris Revitalift Derm Intensives Hyaluronic Acid and Caffeine Eye Serum — $20.00

I’ve tried multiple serums and Ayurvedic methods, like turmeric masks and tea bags, to reduce the presence of my dark circles—especially on days when I was going au natural with my makeup. Though these methods helped, I knew I couldn’t bring a jar of turmeric with me on a recent trip to the Cannes Film Festival… where I knew I’d be faced with many nights of partying and days of nonstop networking (in other words, exhaustion and stress). Knowing I wanted to keep my under eyes looking their best at such an important event, I decided to swap my usual methods for the L’Oréal Paris Revitalift Derm Intensives Hyaluronic Acid and Caffeine Eye Serum ($20), which has more than 30,000 five-star reviews on Amazon. In this high-pressure situation, my fingers were certainly crossed in hopes that it would live up to the hype.

The serum contains 2.5 percent hyaluronic acid and caffeine, which work together to address specific concerns in the eye area. According to Rebecca Marcus, MD, a board-certified dermatologist and founder of Maei MD, hyaluronic acid is a powerhouse ingredient that hydrates and plums the skin, minimizing the appearance of fine lines. The Revitalift Filler Eye Serum contains macro and micro hyaluronic acid, which have different-sized molecules that penetrate the skin at different levels to ensure peak hydration. This multi-molecular approach also offers plumping benefits, which smooths out lines around the eyes and reduces the appearance of wrinkles.

The other key ingredient here is pure caffeine, which essentially wakes up your under-eye area to the same degree that drinking coffee wakes your brain and body. When applied topically, caffeine works as a vasoconstrictor, meaning that it constricts blood vessels and reduces inflammation in a way that makes it effective for minimizing dark circles and puffiness. In addition to these instant effects, caffeine also acts as a powerful antioxidant and staves off free radical damage to prevent signs of visible skin aging over time.

“The delicate under-eye area can benefit from both the hydrating properties of hyaluronic acid and the vasoconstricting properties of caffeine, which may help it appear brighter and less puffy,” confirms Dr. Marcus.

Also present in the formula is glycerin, which derms praise as the best “no bells and whistles” skin hydrator. It’s super gentle and acts as a humectant to draw water into the skin, leaving behind a moisturized, radiant result.

When it came time to test the serum for myself, I used it every day for a week straight on bare skin immediately after cleansing my face. The applicator is designed with three stainless steel balls that offer a cooling effect that further helps to reduce puffiness—which I loved. I only needed a few drops of product to refresh my tired eyes, and it was so easy to apply before topping it off with my usual moisturizer, sunscreen, and makeup.

Speaking of, the serum is designed to layer well under any concealer or foundation because its clear liquid formula quickly absorbs into the skin without leaving any greasy or oily residue. For someone who had to stand under the glaring sun of the French Riviera, this was a pleasant surprise. During the summer, my skin tends to be dryer and breaks out if there’s excessive sweat and oil on it. Thankfully, this serum is formulated to work on all skin tones and textures throughout all seasons.

After a week of continued use, I felt that my under-eye bags were lighter than usual. There were days on my trip to Cannes when I only applied some light concealer, and my skin looked evenly textured. In photographs, my under-eye bags were nearly invisible. If this was the result after a week, I can’t wait to see what a month will do.