Kiehl's Powerful-Strength Vitamin C Face Serum — 12.5% Vitamin C with Hyaluronic Acid, Lightweight Brightening & Texture-Improving

Kiehl's Powerful-Strength Vitamin C Face Serum is a lightweight, daily serum with 12.5% pure Vitamin C and hyaluronic acid designed to brighten skin, improve texture, and reduce the appearance of fine lines and deep-set wrinkles.

This face serum combines a concentrated dose of L-ascorbic acid (12.5% Vitamin C) with hydrating hyaluronic acid in a stable, patent-backed formula. It’s formulated to deliver antioxidant support while smoothing and firming skin over time. Clinical testing over eight weeks shows measurable improvements in texture and radiance, with visible reductions in fine lines from two weeks and deeper wrinkle improvements over a month.

How quickly will I see results from this Vitamin C serum?

Results follow a progressive timeline based on clinical testing: immediate improvements in texture and radiance were recorded, with noticeable reduction in fine lines after two weeks and further reduction in deeper wrinkles after four weeks. Consistent twice-daily use supports these outcomes.

• Immediate: texture and surface radiance improvements reported.
• 2 weeks: visible reduction in fine lines.
• 4 weeks: reductions in deeper, set-in wrinkles.
• 8 weeks: sustained improvements in overall skin smoothness and firmness per study results.

What are the key ingredients and how do they help my skin?

The serum centers on 12.5% pure Vitamin C (L-ascorbic acid) for antioxidant support and brightness, paired with hyaluronic acid to attract and hold moisture. The combination aims to brighten dull skin, improve texture, and plump the look of fine lines without feeling heavy.

• 12.5% L-ascorbic acid: concentrated antioxidant to boost radiance and help even skin tone.
• Hyaluronic acid: hydrates and helps plump the skin surface for smoother appearance.
• Patented stable formula: maintains Vitamin C potency while being suitable for many skin types.
• Lightweight texture: absorbs quickly under moisturizers and sunscreen.

How should I add this serum into my daily routine?

Use the serum morning and night after cleansing and toning and before applying moisturizer. Dispense two pumps, smooth over the face avoiding the immediate eye area, and follow with your regular hydration and sun protection in the morning.

• When: morning and evening after cleansing and toning.
• How much: two pumps per application for full-face coverage.
• Order: serum first, then moisturizer, then sunscreen in daytime routines.
• Patch test: advisable for sensitive skin before full use.

Is this serum suitable for sensitive or all skin types?

The formula is designed to be highly stable and to balance a potent Vitamin C concentration with a lightweight, hydrating base that many skin types can tolerate. Sensitive skin users should introduce the product gradually and perform a patch test to confirm comfort.

• Suitable: formulated for all skin types, including those prone to sensitivity.
• Stability: patented formula helps preserve Vitamin C effectiveness.
• Introduce slowly: start with once-daily use if you have reactive skin.
• Avoid contact: keep product away from the immediate eye area.

Who this is for: This serum is for anyone seeking a concentrated Vitamin C treatment that targets dullness, uneven texture, and the visible appearance of lines and wrinkles while delivering hydration. It suits people who want a stable, clinically tested antioxidant boost that layers easily under moisturizers and sunscreen—especially those committed to a twice-daily skincare routine and gradual improvement over weeks.

Ingredients

Propylene Glycol, Dimethicone, Glycerin, Ascorbic Acid, Ethylhexyl Palmitate, Cetyl PEG/PPG-10/1 Dimethicone, Dimethicone Crosspolymer, Ascorbyl Glucoside, Cyclohexasiloxane, Hydroxyethylpiperazine Ethane Sulfonic Acid, Lauroyl Lysine, Acrylonitrile/Methyl Methacrylate/Vinylidene Chloride Copolymer, Polysilicone-11, Adenosine, Hydrolyzed Hyaluronic Acid, Limonene, Isobutane, Citrus Aurantium Dulcis (Orange) Peel Oil, Citrus Limon Peel Oil/Lemon Peel Oil, Citral, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate.