C15 Super Booster
Reviewed by SerumTruth Editorial · Updated July 2026
A well-formulated 15% L-ascorbic acid serum with the classic antioxidant trio and packaging built to protect it, which is the right priority for this active. The small 20ml size and mid-tier price make it dear per ml. On formulation and stability, it is one of the stronger vitamin C picks.
- 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.
- Potency21 / 25
Dosed at studied levels, not fairy-dusted
- Vitamin C (L-Ascorbic Acid) (15%): dosed at a studied level
- Vitamin E (Tocopherol): dosed at a studied level
- Ferulic Acid: dosed at a studied level
- Potency tracks how strongly the actives are dosed, led by the strongest, not how many there are.
- Delivery & stability16 / 20
Delivery tech + packaging that protects fragile actives
- Delivery: standard
- Packaging: airless, opaque
- Air- or light-sensitive actives (Vitamin C (L-Ascorbic Acid), Vitamin E (Tocopherol), Ferulic Acid), so packaging is scored.
- Formulation7 / 10
Disclosure, active breadth, and ingredient generation
- 1 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
- Value7 / 15
What a month of use costs vs. the category
- About $44 per month to use
- $49 for 20 ml, used about twice a day (about 0.3 ml each time), so a bottle lasts about 1.1 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) | n/a | Studied |
| Ferulic Acid | n/a | Studied |
15% L-ascorbic acid with vitamin E, ferulic acid, ergothioneine and two peptides, built around a disclosed 15%, in an opaque, UV-coated glass bottle with an air-restricting dropper. The packaging is engineered to slow the oxidation that afflicts pure vitamin C, and the antioxidant core is the well-studied CE-ferulic idea with extras. It is a concentrated booster meant to layer.
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.