The Redken Acidic Grow Full System Instant Densifying Spray for Thin Hair is designed to help restore balance to the scalp. Formulated with azelaic acid and a 5% densifying complex, the lightweight mist aims to strengthen the hair fibre to promote denser-looking strands. Delivering targeted hydration to both the scalp and hair, this formula helps to defend against further breakage for healthier-looking, more resilient hair.