Understanding Vitamin C’s Skincare Benefits

While some skincare formulas serve a singular purpose, others deliver multiple functions – and vitamin C serum falls firmly into the latter category. What’s more, this hero antioxidant is one of the most potent weapons you can introduce into your skincare arsenal.

For mature, oily, dry and sensitive skin types, vitamin C’s brightening and protective properties contribute to the overall balance and appearance of your skin. Outside of serums, vitamin C skincare benefits can be delivered through moisturisers, toners and exfoliators.

In this go-to guide, we’ve compiled a list of vitamin C benefits for skin, so you can add this powerful ingredient to your routine and achieve glowing, healthier-looking skin.

What is vitamin C?

Vitamin C is an antioxidant that can provide a range of protective, brightening and anti-ageing benefits for the skin.

Since the body does not produce vitamin C, it has to be applied topically to the skin. There are several different forms and concentrations of vitamin C used in skincare:

L-ascorbic acid – the purest form of vitamin C, this highly efficacious, water-soluble vitamin is absorbed into the skin and starts working upon skin contact. Although powerful, L-ascorbic acid is quite unstable and more prone to oxidation (when a substance comes into contact with oxygen) than vitamin C derivates. When pure vitamin C oxidises, it darkens in colour and loses its potency.
Vitamin Cg (ascorbyl glucoside) – this derivative of vitamin C activates once it is absorbed into the upper layers of the skin. Vitamin Cg is formulated in many of our anti-wrinkle formulas to smooth the appearance of fine lines. Kiehl’s follows green science practices to synthesise vitamin Cg, which makes it a renewable ingredient.
Activated C – a highly stable version of vitamin C, activated C is engineered in Kiehl’s labs. This specialised derivative is particularly effective for reducing the appearance of dark spots and hyperpigmentation, so you can still enjoy the skincare benefits of vitamin C – without experiencing the same levels of sensitivity you might get with pure vitamin C.

5 benefits of vitamin C serum

Thanks to its status as an antioxidant, there are many vitamin C benefits for skin. Vitamin C:

Neutralises free radicals that damage the skin
Brightens and unifies skin tone
Stimulates collagen production to reduce the look of fine lines
Diminishes the appearance of blemish-prone skin
Tackles signs of hyperpigmentation

Read on to find out how vitamin C is good for skin and which products you can incorporate into your skincare ritual to get the most out of this ingredient.

Neutralises free radicals

When we talk about the benefits of vitamin C serum and other vitamin C-rich skincare products, antioxidant protection against free radicals is at the very top of the list.

Every day our skin is exposed to outside aggressors like UV damage and pollution. These aggressors can trigger oxidation in the body, which creates unstable molecules known as ‘free radicals’. When free radicals outnumber antioxidants in the skin, it can lead to oxidative stress – which can accelerate visible signs of ageing like fine lines and hyperpigmentation.¹

Since vitamin C is an antioxidant, it inhibits these free radicals. This puts a stop to oxidative stress and protects your skin cells from damage.

Brightens dull skin and evens skin tone

Dull skin can affect a variety of skin types, though it’s often most common with dry and mature skin types (those lacking in water and natural lipids).

A lacklustre skin tone also appears more uneven because it doesn’t uniformly reflect light. External stressors like UV rays and pollution largely contribute to skin dullness, which is where using vitamin C skincare benefits your overall skin tone.

After cleansing, tackle dull skin with our Clearly Corrective™ Brightening & Soothing Treatment Water to refresh your complexion and encourage more radiant, refined skin. Then, lock in hydration with the Clearly CorrectiveTM Brightening & Smoothing Moisture Treatment, a brightening moisturiser that utilises the efficacious combination of activated C and glycolic acid to increase clarity and brightness.

The result? A luminous, more unified complexion.

Boosts collagen and reduce fine lines

As we age, our skin undergoes a gradual loss of elastin and collagen, which results in sagging skin. One of the most notable vitamin C benefits for skin, then, is its unique ability to synthesise collagen in skin² by stabilising collagen molecules.

To visibly reduce the appearance of fine lines and wrinkles, our Powerful-Strength Line-Reducing Concentrate is formulated with 12.5% pure vitamin C and vitamin Cg. To manage dark circles and lines around the especially thin eye area, we suggest a targeted vitamin C serum specifically for the eye contour. Our Powerful-Strength Line-Reducing & Dark Circle-Diminishing Vitamin C Eye Serum counteracts crow’s feet and puffiness, too – to promote brighter, plumper skin.

Supports blemish-prone skin

Regular application of vitamin C serum benefits the skin by diminishing the redness and swelling associated with breakouts. When your skin is in a post-blemish state, topical vitamin C can also help reduce the appearance of post-blemish marks, which can typically take months – or even years – to fade.

You can integrate vitamin C skincare benefits into a mild acne-prone skincare routine easily, with one notable exception. If you’re using retinol-based blemish products, avoid applying them in the same routine as vitamin C. (In this case, we suggest using vitamin C in the morning and retinol at night).

While there is some hesitancy around using a combination of vitamin C and chemical exfoliants, the payoff can be worth it for blemish-prone skin. The trick is to use the right concentrations and monitor your skin for sensitivity. Many of our plant-based formulas for breakouts contain salicylic acid, which is enhanced by vitamin C for even more beneficial results.

Targets hyperpigmentation

We know that the skincare benefits of vitamin C include evening out skin tone, but this powerful antioxidant is particularly useful for targeting different forms of hyperpigmentation, too. As a quick guide to hyperpigmentation and dark spots, the three main types include:

Sun spots or ‘age spots’ – brown, tan, or dark spots caused by prolonged exposure to UV rays.
Melasma – larger patches of discoloured skin that are caused by genetic, hormonal, and environmental factors.
Post-inflammatory marks – tan or brown discolouration that appears after the skin has experienced ‘trauma’ of some kind: such as sunburn, a cut or wound, or the aforementioned post-blemish marks.³

Introducing vitamin C into your skincare routine can effectively block the melanin synthesis that leads to hyperpigmentation. We recommend the Clearly Corrective™ Dark Spot Solution, which uses activated C to helps boost skin clarity and diminish sun spots.

Tips for using vitamin C in your skincare

Even the most potent serum can’t deliver results without proper application. To reap the full benefits of vitamin C serum, then, here are a few tried-and-tested application methods:

Avoid layering vitamin C with potent ingredients (like retinol) as this combination can trigger sensitivity or a damaged skin moisture barrier.
Ensure product is applied on clean, dry skin to allow for maximum effectiveness and absorption.
Massage the product into skin (moving from the centre outwards) to encourage blood flow in the face.
Follow with a moisturiser to help seal in the ingredients, then finish with SPF for UV protection.

By following the correct usage, you can typically see visible results after three to four weeks.

There are so many vitamin C benefits for skin – so now, read up on why this hero ingredient features on our list of summer skincare essentials.
¹https://pmc.ncbi.nlm.nih.gov/articles/PMC3249911/
²https://pmc.ncbi.nlm.nih.gov/articles/PMC7802860/
³https://dermnetnz.org/topics/postinflammatory-hyperpigmentation