Ferulic Acid
A plant antioxidant that supercharges vitamins C and E — very low allergy, best known from the "CEF" serum stack
INCIFerulic Acid
- Category
- Antioxidant
- Risk level
- low
- Synergy with C + E
- Ferulic 0.5% + vitamin C 15% + vitamin E 1% can give several-fold more photoprotection than vitamin C alone
- Plant origin
- Found in rice bran, oats, apples, and seed oils
- Stabiliser
- Slows oxidation of vitamin C and helps hold the formula's pH
- Tolerability
- Very low allergy; the main "issue" is normal yellow colour
Look for these names on ingredient lists
This ingredient may appear under any of these names:
Commonly found in
Possible reactions
- Contact dermatitis very rare (well under 0.1%)
- Mild stinging on broken/sensitised skin (often from the low-pH vitamin C alongside it)
- Yellowish tint is normal, not a sign of damage
- Pregnancy-safe
Top picks with Ferulic Acid
Highly rated products that feature Ferulic Acid in their ingredient list.
Always scan the actual label before use — formulations change.
What is ferulic acid?
Ferulic acid is a small phenolic antioxidant found in the cell walls of plants — rice bran, oats, apples, and various seeds — where it acts as both a UV defence and an antioxidant. Topically it does the same two things: it neutralises free radicals and stabilises vitamins C and E, extending their life and amplifying their benefits.
Its claim to fame is the CEF stack (vitamin C + vitamin E + ferulic acid), popularised by SkinCeuticals C E Ferulic. Peer-reviewed Duke dermatology research showed that adding ~0.5% ferulic acid to a C+E serum boosts photoprotection several-fold — a genuine, replicated finding, not marketing.
Why it's almost never a problem
Ferulic acid is one of the gentlest antioxidants in cosmetics — patch-test contact dermatitis is well under 0.1%, and it's rated safe at the levels used (0.1–1%, usually 0.5%) and is pregnancy-safe.
The main things to know are cosmetic, not safety:
- Colour. Ferulic acid is yellow-orange, so CEF serums look yellow — that's normal. Dark amber/brown means the vitamin C has oxidised and the serum should be replaced.
- Sting comes from the vitamin C. Ferulic acid lowers a C serum's working pH, so a CEF can sting slightly more than a derivative serum — that's the acidity, not the ferulic acid.
How to use it well
- Use it in a CEF serum (it's rarely sold alone).
- Apply in the morning — the whole point is daytime photoprotection.
- Pair with daily SPF — it boosts sunscreen, doesn't replace it.
- Watch the colour — yellow fine; brown = replace.
- Buy small bottles to finish before they oxidise.
Alternatives
- Non-stinging antioxidants: vitamin E alone, resveratrol, green-tea polyphenols, astaxanthin.
- Can't tolerate CEF's low pH: a vitamin C derivative (SAP, MAP, THD ascorbate) plus a separate antioxidant.
- Gentle brightening: niacinamide, alpha arbutin, azelaic acid.
The bottom line
Ferulic acid is the quiet stabiliser that makes vitamin C + E serums work harder — very low-allergy, evidence-backed, and only "quirky" in that it's meant to look yellow. If a CEF stings, the acidity (not the ferulic acid) is the cause.
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References & further reading
- Ferulic acid stabilises a topical C+E antioxidant (Duke research) PubMed / J Invest Dermatol
- Antioxidants in skin care — overview DermNet