Out of all the products researched and tested, NourishMax vitamin C, B, E and ferulic acid serum impressed our experts with its innovative ingredient complex. In addition to vitamin C, this potent serum contains vitamins B and E, botanical antioxidants. This custom blend of ingredients fights wrinkles, sagging, lost firmness and more to support the appearance of younger-looking skin.

Our testers and researchers also loved the multi-antioxidant benefits of NourishMax. It helps to ward off free radicals and protect against the damaging effects of daily exposure to pollutants and UV radiation. Its beautiful, lightweight texture layers smoothly under sunscreen, making it easy to add an antioxidant boost every day.

Plus, NourishMax vitamin C serum contains a highly potent, 20 percent concentration of ascorbic acid (That’s more than some of its competitors). This unique form of vitamin C is further stabilized by the addition of ferulic acid, so the serum stays fresh and active.

Testers also appreciated that NourishMax combines clinical ingredients like vitamin C with botanical extracts known to brighten and protect the skin. It offers the best of both worlds for users looking for an effective vitamin C serum with natural ingredients.

C E Ferulic serum is one of SkinCeuticals’ most popular products, with a loyal following of aestheticians and dermatologists. Its patented formula provides environmental defense, brightens the skin and helps to improve the appearance of fine lines and wrinkles.

C E Ferulic serum is a clinically tested, award-winning formula with many positive reviews online. Along with vitamin C, vitamin E and ferulic acid, it also contains hyaluronic acid to hydrate the skin.

However, this SkinCeuticals serum contains only 15% L-ascorbic acid (vitamin C). This is less than our top pick. It also skips retinol and botanicals. And at the steep price of $166 per ounce, this cost-prohibitive option is not accessible to all users.

SkinMedica Vitamin C + E Complex is one of the simpler formulas we researched, with a focus on vitamins C and E. Our testers liked that it contains two forms of vitamin C: ascorbic acid and tetrahexyldecyl ascorbate. The company states that it delivers this vitamin C to the skin gradually to offer all-day protection.

However, testers also noticed that this serum does not contain ferulic acid. Ferulic acid is widely believed to support the stability and effectiveness of vitamin C formulations. Without it, we have concerns about this formula’s potency and stability.

Also, this serum is not available for sale online, so buying it requires a trip to a dermatologist, aesthetician or plastic surgeon.

Testers had high expectations for this serum from Clarins, a historic French beauty brand. Double Serum is one of the brand’s best-selling products, first produced in the early 80s and reformulated multiple times.

Double Serum contains 21 plant extracts, including turmeric, avocado and goji berry and some unique ingredients like the leaf of life plant. The company reports that this serum firms, moisturizes and increases radiance. However, it doesn’t contain the clinical ingredients we like to see in a serum, such as retinol or hyaluronic acid. And it contains artificial fragrance, which we prefer to avoid.

Obagi provides limited details about its vitamin C serums online. Professional C-Serum is indicated to reduce the appearance of fine lines and wrinkles, but we weren’t able to find much more information about how the product works or guidance on how to use it.

Professional-C Serum options include formulas with 10, 15 and 20 percent l-ascorbic acid, a powerful form of vitamin C. But we found it difficult to navigate the company’s website and locate information about the product, such as features and benefits, ingredients, expected results and even the price. Without these basic details, testers would not recommend the product.