To buy: $10; amazon.com. With age comes the loss of collagen in the skin, Yadav says. “The idea behind collagen is that it will provide anti-aging benefits, like diminishing fine lines and adding volume,” she says. “While collagen isn’t going to give you dramatic anti-aging results, it can help improve radiance, which creates a youthful look.” To get the most of this particular item, L’Oreal recommends using it every day or night after cleansing the skin. One user saw results in as little as two weeks, writing, “It works! It’s amazing and makes my face and neck feel so smooth. I’m 46. I don’t wear tons of makeup and don’t go into the sun a lot, but I’m starting to get wrinkles. This stuff has minimized all the fine lines.” As for what you can expect, L’Oreal suggests giving the moisturizer up to four weeks to fully work. Those with sensitive skin particularly love that the formula is fragrance-free, sharing, “My skin is sensitive and breaks out with many moisturizers. Not this one! It feels kinda thick but don’t worry it doesn’t clog pores! I will buy this again! It is now added to my daily routine! Makes my skin look fuller and lines aren’t as defined on my face and neck.” Unlike other popular anti-aging skincare ingredients, collagen is relatively safe for most skin types, Yadav says. “Collagen is very gentle and should not cause side effects like a more acidic ingredient, such as retinol. As with any skincare ingredient, there is the possibility for irritation and even an allergic reaction. If this happens, you should discontinue use and consult a dermatologist to dive in deeper.”