Free Radical Scavengers

Antioxidants

Neutralise oxidative stress caused by UV exposure, pollution, and metabolic processes

Ingredients

Mechanism of Action

How It Works

Antioxidants donate electrons to unstable free radicals (reactive oxygen species) generated by UV exposure, pollution, and normal metabolic activity, neutralising them before they can damage collagen, lipids, and DNA. Vitamin C (L-ascorbic acid) is the most studied, inhibiting melanin synthesis, supporting collagen production, and working synergistically with vitamin E and ferulic acid. Different antioxidants operate at different cellular levels, so combining them provides broader protection than any single ingredient.

Best For

All skin types as daily preventative care
Sun-damaged skin
Dull or uneven complexion
People living in urban environments with high pollution exposure

Watch Out For

L-ascorbic acid is unstable; choose products in dark or airless packaging
High-concentration vitamin C (above 15 to 20%) can irritate sensitive skin
Some antioxidants, such as resveratrol, can oxidise quickly after a product is opened
Antioxidants complement SPF but do not replace it

What to Look For

Key Ingredients

Tap an ingredient to learn more

Vitamin C (L-Ascorbic Acid)

Brightens skin, supports collagen synthesis, and neutralises UV-induced free radicals

Tocopherol (Vitamin E)

A fat-soluble antioxidant that works synergistically alongside vitamin C

Ferulic Acid

A plant-derived antioxidant that doubles the efficacy of vitamins C and E

Resveratrol

A polyphenol antioxidant with anti-inflammatory and anti-ageing properties

Niacinamide

Reduces oxidative stress while regulating sebum production and melanin transfer

How to Use

Routine & Layering

Best used AM

Apply antioxidant serums in the morning after cleansing and before SPF. Vitamin C works synergistically with sunscreen to extend UV protection and neutralise the free radicals that SPF alone does not block. Apply to clean, dry skin and allow it to absorb fully before moisturiser and SPF.

AM Routine

The combination of vitamin C, vitamin E, and ferulic acid (a classic trio) provides the most robust daytime antioxidant protection. Apply before SPF without exception.

PM Routine

Some antioxidants such as resveratrol and niacinamide are effective in the evening too. Vitamin C is best reserved for the morning, as its role in photoprotection is most relevant during the day.

Layering Order

1 Cleanser
2 Antioxidant serum (vitamin C or similar)
3 Moisturiser
4 SPF

Compatibility

Pairings & Interactions

Pairs Well With

Mineral UV Filters

Antioxidants and SPF together provide more complete photoprotection than either does alone

Brightening & Depigmentation

Vitamin C inhibits melanin synthesis and is a natural pairing with other brightening actives

Hydrating & Barrier Support

Layering a hydrating serum or moisturiser over an antioxidant serum maintains the moisture gradient needed for healthy skin function

Avoid Combining With

Retinoids

L-ascorbic acid at low pH can destabilise retinoids; keep vitamin C in the AM and retinoids in the PM

Peptides & Signal Molecules

Copper peptides and vitamin C can oxidise each other; use them in separate routines (AM vs PM)

Got Questions?

Frequently Asked Questions

When is the best time to apply an antioxidant serum?

Morning is the most important time for antioxidant use, as their primary role is defending against UV-triggered and pollution-triggered oxidative stress during the day. Applying after cleansing and before SPF makes them most effective.

Why is vitamin C so hard to formulate with?

L-ascorbic acid (the most effective form of vitamin C) is inherently unstable and oxidises when exposed to light, air, and heat. Once oxidised, it can paradoxically cause skin discolouration rather than brightening it. Look for products in dark glass or airless pump packaging, and discard if the formula has turned orange or brown.

What is the difference between L-ascorbic acid and other vitamin C derivatives?

L-ascorbic acid is the active form of vitamin C and the most studied. Derivatives such as ascorbyl glucoside, sodium ascorbyl phosphate, and ascorbyl tetraisopalmitate are more stable but need to convert to L-ascorbic acid in the skin, which reduces their potency. They are a useful option for sensitive skin that cannot tolerate pure L-ascorbic acid.

Do antioxidants replace SPF?

No. Antioxidants neutralise some of the free radical damage that occurs when UV reaches the skin, but they do not block UV radiation in the way a sunscreen does. They are a complementary layer of protection, not a substitute.

Can I use vitamin C alongside niacinamide?

Yes. The older concern that combining vitamin C and niacinamide causes skin flushing or cancels out their effects has not been supported by current evidence. They can be used together in the same routine or layered without issue.

Curated List