What It Is: A concentrated facial serum formulated with just seven ingredients to help step up your smoothness by visibly refining the skin's texture and minimizing the appearance of pores. Product Details: With 9.8% Glycolic Acid, this serum is formulated with just seven ingredients to help visibly refine and smooth skin's texture and boost skin's glow. Free of fragrance and colorants, this concentrated serum is minimally formulated for skin absorption and smoothing effect. Key Ingredients: Glycolic Acid is a naturally occurring fruit acid derived from sugar cane known to help smooth skin. Results: After 1 Week, 98% Agree Skin Feels Softer* Instantly, 83% Felt Refined Texture* Smoother Skin in 1 Week** *Reported by consumers in a 4-week study. **Expert grading in a 4-week clinical study. How to Use: In the evening, apply 2–3 drops to clean, dry skin. Try out Kiehl's Glycolic Acid serum skin hacks below: Zone treat your face by applying Glycolic Acid Serum to areas prone to roughness. Follow with your favorite moisturizer where needed. Use as an exfoliating treatment for cracked heels. Layer with Kiehl's Hyaluronic Acid Serum to hydrate & rebalance skin's moisture. Layer with Kiehl's Niacinamide Serum to reduce oil & soothe skin. 1 oz./ 30 mL Ingredients^: Aqua/Water, Glycolic Acid, Glycerin, Alcohol Denat., Sodium Hydroxide, Sodium Hyaluronate, Hydroxyethylcellulose *Please Note: This ingredient list is subject to change. Please refer to the product packaging for the most up-to-date ingredient list.