Beauty Skincare Over One Million Bottles of This Glow-Boosting Exfoliating Toner Have Sold Since Its Launch “The dead skin just lifts away without irritation.” By Maya Gandara Maya Gandara Maya Gandara is an Ecommerce Writer covering beauty, fashion, and lifestyle at Meredith. When not testing the latest buzzy skincare, you can find her shooting film photography around Brooklyn or cozying up with a good novel. InStyle's editorial guidelines Published on March 3, 2022 @ 11:00PM Pin Share Tweet Email We independently research, test, review, and recommend the best products—learn more about our process. If you buy something through our links, we may earn a commission. Photo: Ren Skincare Understanding which exfoliating acids are right for your skin can be tricky (here's a quick rundown of several kinds), especially for those with ultra-sensitive complexions. If you're unsure where to begin, lactic acid may be an ideal starting point; it's considered one of the most gentle exfoliating ingredients in skincare. Take the Ren Skincare Ready Steady Glow Daily AHA Tonic, a lactic acid-based daily toner, as proof of the acid's popularity — it's sold over one million bottles to date for its ability to transform skin concerns with little to no irritation. The skin-resurfacing formula smoothes out fine lines and wrinkles, tightens sagging, brightens dullness, buffs away uneven texture, and balances out skin tone with every use. Two key ingredients work alongside lactic acid in improving the skin: salicin, a natural acne treatment produced from willow bark extract, greatly reduces pore size and minimizes oil production, while azelaic acid reduces inflammation, redness, and acne scarring. Courtesy Shop now: $39; usa.renskincare.com Introducing exfoliating acids into your regimen may sound intimidating, but lactic acid is one of the safest choices you could make. It penetrates the skin less aggressively than other acids, yet still has the ability to provide serious anti-aging benefits and pave the way for other skincare to absorb more effectively — all while ensuring a less severe purging period, if any at all. As Dr. Michele Green, a board-certified cosmetic dermatologist in New York City, previously told InStyle, "lactic acid is best used on sensitive skin because it is a mild exfoliant that will not disrupt the pH of the skin or cause redness and irritation." People With Thin, Fine Hair Say This Shampoo Adds a Fullness That Lasts Verification of the toner's results can be found within the product's reviews section, where over 2,600 Ren Skincare shoppers have left five-star ratings and positive remarks. Many share that the formula has controlled adult acne, given their skin a "lovely glow," and faded dark marks and scars, all without leaving a harsh reaction behind. "This is the only toner I'll use. When I don't, my skin just does not glow the same. It looks dull and I can tell the difference," wrote one person. "This has completely changed my skin for the better! I had really bad acne … and my skin has become completely new! Refreshed, glowing, and acne free," added a second. "My skin is more bright and youthful," claimed another. "The dead skin just lifts away without irritation." Ren Skincare's best-selling Ready Steady Glow Daily AHA Tonic is available for $39 per bottle. Pick up other favorites from the brand's Radiance line, too.