Kiehl's Powerful-Strength Line-Reducing Concentrate, 3.4 oz – 12.5% Vitamin C & Hyaluronic Acid Serum

A cult-favorite in Kiehl's skincare lineup, Powerful-Strength Line-Reducing Concentrate delivers a potent, dual-form vitamin C complex at a concentration higher than most vitamin C serums on the market. The formula combines Pure Vitamin C (L-Ascorbic Acid) and Vitamin Cg (Ascorbyl Glucoside) — together totaling 12.5% vitamin C — for a highly efficacious antioxidant blend known for its ability to improve the visible appearance of skin aging. Pure Vitamin C helps boost radiance, improve texture, and visibly reduce the appearance of lines, wrinkles, and other signs of aging, while Vitamin Cg activates once absorbed into the skin's surface for continued antioxidant benefit.

Kiehl's uses a patented, stabilized Vitamin C technology so the formula penetrates skin's deeper surface layers and remains effective in skin for up to 6 days. The serum is further enriched with Fragmented Hyaluronic Acid, which acts like a sponge to draw moisture into the skin's surface layers and expand as it absorbs — known for its ability to smooth, plump, and visibly reduce the appearance of facial lines while refining texture.

This lightweight concentrate is carefully formulated and tested to be gentle enough for sensitive skin, and is suitable for all skin types. As with most potent vitamin C formulas, Kiehl's recommends starting with once-daily use and gradually building to twice-daily application as your skin adjusts.

✨ Key Ingredients:

Pure Vitamin C / L-Ascorbic Acid (10.5%): A highly efficacious antioxidant known to help boost radiance, improve texture, and visibly reduce the appearance of lines and wrinkles
Vitamin Cg / Ascorbyl Glucoside (2%): A vitamin C derivative that activates in the skin's surface layers, frequently used in anti-wrinkle formulas
Fragmented Hyaluronic Acid: Draws and holds moisture at the skin's surface, supporting a smoother, plumper look