C E Ferulic
Reviewed by SerumTruth Editorial · Updated July 2026
The strong-evidence anchor of the whole category, the antioxidant combination with the deepest published record for the appearance of brightness and environmental defence. It also costs like a flagship, and the tinted-glass dropper means the clock starts ticking the day you open it. You are paying for the original and for genuinely strong evidence. The dupes exist for a reason.
- Evidence24 / 30
Strength of the research behind the key actives
- Vitamin C (L-Ascorbic Acid): strong evidence
- Vitamin E (Tocopherol): moderate evidence
- Ferulic Acid: moderate evidence
- Score is the average of the key actives’ evidence grades.
- Potency24 / 25
Dosed at studied levels, not fairy-dusted
- Vitamin C (L-Ascorbic Acid) (15%): dosed at a studied level
- Vitamin E (Tocopherol) (1%): dosed at a clinical, high-end level for its category
- Ferulic Acid (0.5%): dosed at a studied level
- Potency tracks how strongly the actives are dosed, led by the strongest, not how many there are.
- Delivery & stability12 / 20
Delivery tech + packaging that protects fragile actives
- Delivery: standard
- Packaging: tinted glass
- Air- or light-sensitive actives (Vitamin C (L-Ascorbic Acid), Vitamin E (Tocopherol), Ferulic Acid), so packaging is scored.
- Formulation10 / 10
Disclosure, active breadth, and ingredient generation
- 3 of 3 actives disclose a concentration
- 3 key actives (breadth credit caps at 3)
- Current-generation or synergistic: Vitamin C (L-Ascorbic Acid), Vitamin E (Tocopherol), Ferulic Acid
- Value3 / 15
What a month of use costs vs. the category
- About $111 per month to use
- $185 for 30 ml, used about twice a day (about 0.3 ml each time), so a bottle lasts about 1.7 months
- Band: $6/month or less earns full marks, $60/month or more hits the floor.
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What’s inside
| Active | Disclosed | Dose |
|---|---|---|
| Vitamin C (L-Ascorbic Acid) | 15% | Studied |
| Vitamin E (Tocopherol) | 1% | Clinical |
| Ferulic Acid | 0.5% | Studied |
The reference antioxidant serum: 15% pure L-ascorbic acid with 1% vitamin E and 0.5% ferulic acid, at the low pH the science requires. This is the trio the original Duke patent built and that every "CE" serum since has chased. Ferulic sits below the 1% line by design, to stabilise the vitamin C, not to pad the label. The amber tinted-glass dropper is the compromise: better than clear, though this formula browns once it is opened and air gets in.
How it’s delivered
Air- and light-sensitive actives (vitamin C, copper peptides) lose potency fast in the wrong packaging, so delivery and the bottle are scored, not just what’s on the label.
The actives, explained
Cosmetic information for general education, not medical advice. The SerumProof score reflects our reading of publicly available research and formulation disclosures. See how scoring works.