While most vitamin C face serums are applied in the morning (to protect skin throughout the day), this formula is best used at night. Containing a higher concentration of vitamin C than many other products -- 18 percent to be exact --this serum helps build collagen while you sleep while also repairing the skin from the damaging exposure it received during the day.

If fine lines and discoloration are messing with your complexion, add this vitamin C serum to your skin-care arsenal. InstaNatural Vitamin C Serum uses both hyaluronic acid and vitamin C to dually fight wrinkles and age spots in order to improve skin's overall tone and texture.

Patented Japanese seaweed encapsulation technology protects the vitamin C in this serum from exposure to light or oxygen -- both known to decrease efficacy --until it's applied directly to skin. Once applied, the tiny capsules burst open to drench your skin in good-for-you antioxidants. Definitely a more exciting way to apply vitamin C to your face.

If you're an urban dweller, you need some extra defense in the form of vitamin C for your skin. Pollution, cigarette smoke and other impurities can dull the complexion, but this serum is packed with valuable ingredients to fight off aggressors. Other than the obvious vitamin C serum benefits, this formula contains an exclusive skincare complex called EUK-134, fluid 02 which helps to carry much-needed oxygen into the skin, as well as soy proteins which can actually help convert those damaging free radicals into healthy oxygen.

As a tried-and-true product, this C-spiked formula follows the similar vitamin C & E cocktail that the others do; however, this one holds quite a few extra antioxidants like lilac leaf cell culture extract, glutathione and ergothioneine. When applied, these ingredients work harmoniously to hydrate and strengthen the skin.