From L’Oréal’s Wonder Water to the Dr Jart+ Cicapair Color Correcting Treatment, a handful of brilliant beauty buys have achieved cult status this year. Right now, though, one product is uniting UK-based skin-care lovers, dermatologists, and aestheticians alike in their obsession: No7 Line Correcting Booster Serum. The serum has been around for a while, but this month, Boots.com — the e-commerce locale of the UK’s leading beauty retailer — revealed that it was their number-one bestselling product. The must-have status makes sense: Currently, a lot more of us are interested in anti-aging skin care and looking for non-invasive ways to minimize fine lines and wrinkles (and, at £38 or $34.99, it’s a fraction of the price of Botox). The pandemic is a contributing factor, with COVID-induced stress and anxiety taking its toll. After what has felt like the longest winter on record, more time spent indoors and around central heating might mean your skin is looking and feeling zapped of moisture and radiance, too. I’ve been a fan of No7 skin care for a long time, ever since the Advanced Retinol 1.5% Complex transformed my skin. In my late 20s, I’m starting to think more about preventative skin care. While I’m pro-aging and believe there is nothing wrong with natural skin changes, lockdown living has resulted in dry under-eyes and subsequently fine lines, which are only emphasized by makeup and affect my confidence. With its thousands of positive reviews, I had to add the serum to my list of hyped products to try. The results were impressive. What’s in No7 Line Correcting Booster Serum, and what are the benefits? Unlike some serums, which can be sticky, No7 Line Correcting Booster Serum feels silky and lightweight, and absorbs in seconds. The star ingredient is Matrixyl 3000+, which Mike Bell, Head of Science Research at No7, explains is a synthetic peptide, or protein. In skin care, proteins act like scaffolding within the skin, keeping it plump and intact and repairing existing damage. “The peptide blend of Matrixyl 3000+ in the Line Correcting Booster Serum is an ideal targeted solution for lines as it stimulates the collagen and elastic that is lost early on in the aging process,” said Dr. Bell in a press release. Another star ingredient is glycerin, which attracts water to the skin, making it hydrated, moisturized, soft, and supple. When skin is well-hydrated, lines are a lot less visible. Dr. Bell says that the serum is clinically proven to reduce the appearance of wrinkles in eight weeks, but the product’s packaging states it can take as little as one week to notice a difference. Does No7 Line Correcting Booster Serum work? While the serum can be used all over the face to reduce fine lines and wrinkles, I wanted to target my under-eyes specifically. I don’t particularly like using eye cream as I find it too heavy and often pore-clogging, so I used the serum instead, concentrating it to my under-eyes and eyelids. My skin is quite sensitive and products applied around my delicate eye area often sting, but this was very soothing. This is skin care, not magic, so I didn’t notice any immediate line-reducing effects but the dry skin around my eyes did become less visible. I’ve been using the serum for just over a week now and, as you can tell, it really does work to iron away lines. In the before image, my under-eye creases extended outwards; looking at the after shot, it’s as though someone has taken an eraser to my skin. In all the years of trying eye serums, balms, and creams, nothing has worked quite as well as this. How should you use No7 Line Correcting Booster Serum? As serums are lightweight in texture, they work best layered under moisturizer. After cleansing in the morning and evening, apply all over or concentrate the serum on target areas, and follow with your moisturizer. For added line-reducing benefits, apply a high-factor, broad-spectrum sunscreen in the morning. (Studies suggest the sun is responsible for a whopping 80% of facial aging signs.) What are the best skin-care products for fine lines and wrinkles? While Matrixyl 3000+ is an exciting ingredient for preventing fine lines and wrinkles, another component dermatologists love is retinol. The No7 serum doesn’t contain this but it’s one of the only clinically-proven ingredients that really tackles and prevents lines on a more permanent basis, as it forces the skin to regenerate at lightning speed. There are downsides to retinol, though: It can cause sensitivity in the form of flaking, redness, and sore skin, and while it works over time, a product with an ingredient like Matrixyl 3000+ instead might be a better option for reactive or sensitive skin. I now understand the hype around No7 Line Correcting Booster Serum — and I’ll use it to the very last drop. At Refinery29, we’re here to help you navigate this overwhelming world of stuff. All of our market picks are independently selected and curated by the editorial team. If you buy something we link to on our site, Refinery29 may earn commission. Like what you see? How about some more R29 goodness, right here?