- Vitamin C: Vitamin Cg, or Ascorbyl Glucoside, is a Vitamin C derivative. With antioxidant benefits, this form of Vitamin C is known to help boost radiance and smooth skin texture.
- Caffeine: an alkaloid known for its stimulating properties. In Kiehl's formulas, it helps energize and reduce dullness.
- Vitamin E: Found in nature and renowned for its proven antioxidant benefits, Vitamin E is known to help neutralize skin-damaging free radicals. In addition to antioxidant protection, Vitamin E is often used in moisturizing skincare products.