Products › Serum › Kiehl's Powerful-Strength Line-Reducing Concentrate 12.5% Vitamin C
Powerful-Strength Line-Reducing Concentrate 12.5% Vitamin C
Powerful-Strength Line-Reducing Concentrate 12.5% Vitamin C is middling — some recognized actives, but dosing or disclosure holds it back.
Actives pyramid
What's actually in it, ranked by how well it's dosed.
What it does
Evidenced benefit intensity, derived from dosed actives.
The receipt
Every point of this grade, traced to the active, its dose, and the evidence.
Vitamin C at 13% — effective dose
Meets the ~8% threshold. 10–20% L-ascorbic acid is photoprotective and brightens tone in clinical data.
Brand clinical study available
The brand has run a clinical/consumer study on this product. Useful, though not independent.
Pros & cons
The honest tradeoffs.
- Vitamin C dosed to the effective threshold (13%)
- Brand has run a clinical/consumer study on this product
Best for
Who and when this fits.
Dupes & alternatives
Cheaper products in the same category that grade equal or higher.
B Timeless Vitamin C + E Ferulic Acid Serum$25
save 65% B Maelove The Glow Maker Vitamin C Serum
$32
save 56% B Paula's Choice C15 Super Booster
$52
save 28% B The Ordinary Ascorbic Acid 8% + Alpha Arbutin 2%
$10
save 86%
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Get Visage VerifiedBased on published concentration thresholds and formulation science. Our algorithm predicts likely efficacy — it does not test the product. Individual results vary. Not evaluated by the FDA. You can't pay to move a grade — Visage Theory is paid only for optional audits and seal licenses, never to change a letter.