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

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

Developed for everyday use, this serum blends a concentrated form of L-ascorbic acid with moisture-binding hyaluronic acid in a stable formula designed to suit a wide range of skin types, including sensitive skin. Clinical testing over eight weeks shows measurable improvements in radiance and skin texture, with visible reductions in fine lines and deeper wrinkles over time. The texture is lightweight and absorbs quickly, making it easy to layer under sunscreen or a moisturizer.

How quickly will I notice brighter, smoother skin?

Users noticed immediate improvements in surface texture and radiance after the first applications, with stronger benefits revealed over weeks of regular use. According to the product testing timeline, fine lines can appear reduced in about two weeks, while deeper lines show more noticeable improvement by week four.

• Immediate: enhanced skin brightness and smoother feel after initial applications
• 2 weeks: measurable reduction in fine lines
• 4 weeks: visible improvement in deeper-set wrinkles
• 8 weeks: continued texture and radiance gains across long-term use

What are the active ingredients and how do they work together?

The formula centers on 12.5% pure L-ascorbic acid (vitamin C) for antioxidant support and glow, paired with hyaluronic acid to help replenish hydration and plump skin. Kiehl's proprietary formulation stabilizes the vitamin C so it remains effective while being gentle enough for many sensitive skin types.

• 12.5% L-ascorbic acid: concentrated antioxidant to boost radiance and target signs of aging
• Hyaluronic acid: hydrates and helps skin look plumper and smoother
• Stable, patented delivery: keeps vitamin C effective longer in the bottle
• Lightweight texture: absorbs quickly for easy layering in routines

How should I include this serum in my daily skincare routine?

Use the serum twice daily, after cleansing and toning, and before applying moisturizer and sunscreen. Apply two pumps to the full face while avoiding the immediate eye area; follow with a suitable moisturizer in the morning and evening.

• Morning and night: apply after cleansing and toning
• Two pumps: enough to cover face without excess product
• Avoid eye area: use dedicated eye products nearby
• Follow with sunscreen in the daytime to protect improvements

Is this suitable for sensitive or all skin types?

The formula is designed to be broadly suitable, including for many people with sensitive skin, because Kiehl's uses a stabilized vitamin C concentration and complementary hydrators. As with any active treatment, start with less frequent use if you have reactive skin and monitor tolerance before increasing to twice daily.

• Formulated for all skin types, including sensitive skin
• Stable vitamin C concentration to reduce potential irritation
• Begin slowly if you have highly reactive skin
• Patch testing recommended prior to full-face routine

Who is this for: This serum is for anyone wanting a concentrated vitamin C treatment that targets dullness, uneven texture, and signs of aging while delivering lightweight hydration. It suits those building a preventative or corrective routine who prefer a fast-absorbing, clinically tested formula that can be layered under moisturizers and sunscreen.

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.