Powerful-Strength Line-Reducing Concentrate
Reviewed by SerumTruth Editorial · Price and formula checked July 2026
A genuinely dosed L-ascorbic acid serum in packaging that respects it, just shy of the very top of the studied range rather than a flagship-strength pour. The ascorbyl glucoside is a stabilizing bonus, not a second proven active, and there is no vitamin E or ferulic acid network backing the antioxidant load the way the category benchmark has. A fair prestige pick if you want L-ascorbic acid without the CE Ferulic price tag.
- Air- or light-sensitive actives in protective, opaque packaging
- 1 listed active is fairy-dusted below the 1% line
- Evidence26 / 30
Strength of the research behind the key actives
- Vitamin C (L-Ascorbic Acid): strong evidence
- Hyaluronic Acid: moderate evidence
The average of the key actives’ evidence grades.
- Potency18 / 25
Dosed at studied levels, not fairy-dusted
- Vitamin C (L-Ascorbic Acid) (10.5%): dosed at a studied level
- Hyaluronic Acid: below the 1% line, treated as fairy-dusted
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)), so packaging is scored.
Delivery tech plus packaging, and packaging only counts when actives are fragile.
- Formulation4 / 10
Disclosure, active breadth, and ingredient generation
- 1 of 2 actives disclose a concentration
- 2 key actives (breadth credit caps at 3)
- No current-generation or synergy bonus
Disclosure, active breadth, and current-generation or synergistic actives.
- Value10 / 15
What a month of use costs vs. the category
- About $28 per month to use
- $79 for 50 ml, used about twice a day (about 0.3 ml each time), so a bottle lasts about 2.8 months
What a month of use costs: full marks at $6 a month or less, the floor at $60 a month or more.
Tap any row to see how its score was built.
Ranks #11 of 27 vitamin c & antioxidants serums we have scored.
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What’s inside
| Active | Disclosed | Dose |
|---|---|---|
| Vitamin C (L-Ascorbic Acid) | 10.5% | Studied |
| Hyaluronic Acid | n/a | Below 1% line |
A water-free, silicone-gel concentrate built on 10.5% L-ascorbic acid plus 2% ascorbyl glucoside (Kiehl’s calls it "Vitamin Cg," a more stable derivative layered in for extended activity, not modeled here as a separate active). Hydrolyzed hyaluronic acid rides low on the ingredient list for a touch of surface hydration. It ships in a frosted, opaque glass bottle on an airless pump, sensible protection for a light- and air-sensitive acid at this pH.
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
What the research says
A 6-month double-blind trial found topical vitamin C linked to a better looking global appearance of photoaged skin versus placebo.
Topical ascorbic acid on photoaged skin. Clinical, topographical and ultrastructural evaluation: double-blind study vs. placebo. Experimental Dermatology, 2003. PubMed ↗
A multicenter study linked a topical hyaluronic acid serum with better looking hydration, tone, and texture over several follow up visits.
Multicenter evaluation of a topical hyaluronic acid serum. Journal of Cosmetic Dermatology, 2022. PubMed ↗
A study of the active, not this exact product. What matters for the score is whether this serum uses it at a comparable dose.
Higher-scoring alternatives
Same category, better SerumProof score. Worth a look before you buy.
Revision history
- July 11, 2026Price and formula rechecked
- July 10, 2026Review published
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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.