To buy: $18; amazon.com More than a moisturizer, this serum also works to prevent signs of aging. Thanks to niacinamide, a form of vitamin B3 that does all sorts of great things for the skin, users can take advantage of the vitamin’s potential to reduce fine lines and wrinkles. Niacinamide also helps clear up acne and works on improving the overall appearance of your skin. Reviewers who’ve tried the product have definitely noticed a difference. “This product is amazing for the price! No breakouts. It’s a very refreshing/soothing consistency. The best part is how glowy it makes me without looking greasy. You literally look like an internal lightbulb was switched on,” one customer wrote. Even those with dry skin saw a difference. “I’ve been using this stuff for a year now and can’t get enough of it. Always wake up with soft smooth skin.” Along with reports of improved skin appearance, a person shared their experience in treating scars and fine lines. “I started to notice my skin becoming so soft and bright. It really helped to lighten my acne scars and keep acne at bay. It also helped with small fine lines.”