Redken Intra-Force System 1 Shampoo for Natural Hair 290ml This Intra-Force System 1 Shampoo works to promote thicker, fuller hair within 30 days of use. Providing a deep yet gentle cleanse, this nourishing shampoo is specially formulated with Zinc PCA, Argininr and Vitamin E which combine to give you super soft, voluptuous locks with up to 95% less breakages.