SkinCeuticals: what the C E Ferulic price actually buys

SkinCeuticals is the dermatologist-office vitamin C brand, owned by L'Oreal. C E Ferulic is its famous serum and costs close to $200 a bottle.

Unusually, the formula itself has published research behind it. Here's what that research shows and where the rest of the line lands.

15% L-ascorbic acid, 1% vitamin E and 0.5% ferulic acid at a low pH. A 2005 study by Lin and colleagues tested this exact combination and found ferulic acid kept the vitamins more stable and doubled the protection against UV damage in skin, compared with vitamins C and E alone.

That's a real result, but it means extra protection under sunscreen, not instead of it. It can tingle, the smell isn't for everyone, and it slowly turns orange as it oxidizes.

• Phloretin CF: vitamin C with phloretin and ferulic acid, pitched for oilier skin.
• Silymarin CF: vitamin C with salicylic acid and milk thistle extract for oily, breakout-prone skin.
• Discoloration Defense: tranexamic acid, kojic acid and niacinamide. All three have studies for discoloration, and together they're a reasonable spot serum.
• Hyaluronic Acid Intensifier (H.A. Intensifier): hyaluronic acid with licorice and purple rice extracts. Hydrating; the plumping claims are mostly about water.
• Triple Lipid Restore 2:4:1: ceramides, cholesterol and fatty acids in a rich cream. Good for barrier support, but pricey.

If you want the exact formula that's been studied and the price doesn't sting, C E Ferulic is a defensible buy. Lots of serums now copy the 15% C, E and ferulic recipe for a fraction of the price, though none share the same study.

For discoloration, the same ingredients come cheaper elsewhere too: niacinamide (our Tone Balance Niacinamide Serum is one option), azelaic acid or tranexamic acid serums. Whatever you choose, daily sunscreen does more for spots than any serum.

Vitamin C is an antioxidant that helps neutralize free radicals made by UV exposure and is needed to make collagen. In skin it has to be in a stable, acidic form to get in, which is why formulation matters so much.

Tranexamic acid and niacinamide work on different steps of the pigment process, which is why they're often combined.

• C E Ferulic style vitamin C, E and ferulic acid for extra photoprotection.limited evidence
• Topical vitamin C for brightness and fine lines.limited evidence
• Tranexamic acid and niacinamide for discoloration.limited evidence

• Claims that a high price equals better results across the line.
• Hyaluronic acid serums permanently plumping skin.