Ducray Squanorm Anti-Dandruff Treatment Shampoo is a gentle shampoo specially formulated to minimize dry dandruff. This particular form of dandruff appears as fine, white or gray flakes that only come off the scalp, and must be combated with specific ingredients, such as pyrithione zinc and glycerin, which are present in this shampoo. The creamy formula provides fast, long-lasting action against dry dandruff, while cleansing and moisturizing the scalp for extra comfort. Dandruff was eliminated by 98%, according to clinical trial volunteers.