Understanding Vitamin C's 5 Key Skincare Benefits for Your Face

Many skincare ingredients serve a specific purpose, while others can perform multiple roles – and vitamin C serum falls firmly into the latter category. In fact, adding this high-performing antioxidant into your skincare arsenal could be your complexion’s next secret weapon.

Whether you have mature, oily, dry or blemish-prone skin, using vitamin C for your face can provide a number of brightening and protective benefits to improve the appearance and texture of your skin. In this guide, we’ll take you through five key vitamin C benefits for skin so you can start integrating this star ingredient into your skincare routine.

What is vitamin C in skincare?

Vitamin C is an antioxidant, and since the body does not naturally produce it naturally, it needs to be applied topically. Vitamin C is most commonly delivered to the skin in serum form, although it’s also formulated in moisturisers, toners and exfoliators, too.

Before we dive into each of the specific vitamin C serum benefits below, let’s examine the different forms that vitamin C can take in skincare:

• L-ascorbic acid – also known as ‘pure vitamin C’, L-ascorbic acid is a highly efficacious form of vitamin C that starts working upon skin contact. This water-soluble vitamin is powerful – but is also known for its instability. L-ascorbic acid is prone to oxidation (the reaction when a substance encounters oxygen), which means it can darken in colour and lose some of its efficacy when applied.
• Vitamin Cg (ascorbyl glucoside) – a derivative of vitamin C, vitamin Cg activates once it is absorbed into the outer layers of the skin. Many of Kiehl’s anti-ageing formulations feature vitamin Cg because it can diminish the look of fine lines and wrinkles. Kiehl’s uses green science to synthesise vitamin Cg – making it a renewable ingredient.
• Activated C – this highly stable version of vitamin C is engineered in Kiehl’s labs. Activated C particularly effective for reducing the appearance of dark spots and hyperpigmentation and, thanks to its stability, any skin type can enjoy vitamin C skincare benefits – without the sensitivity you might experience with pure vitamin C.

Neutralises free radicals

When we talk about vitamin C benefits for skin, antioxidant protection against free radicals is at the very top of the list.
Every day, our skin is exposed to a variety of external aggressors – with UV rays and pollution among the leading culprits. These aggressors trigger oxidation in the body, which in turn creates unstable molecules: free radicals. If the number of free radicals outweighs the number of antioxidants in the skin, it causes oxidative stress. When oxidative stress occurs, it can accelerate visible signs of ageing like hyperpigmentation and fine lines¹.
By applying an antioxidant like vitamin C to the skin’s surface, it effectively blocks these free radicals from forming. This means the skin doesn’t undergo oxidative stress, which protects your skin cells from any subsequent damage.