Jason Thin to Thick Extra Volume Conditioner extra volume Hair Conditioner. Jason's clean rinsing body-building hair conditioner delivers weightless manageability and volume to fine, thinning hair. Hair-strengthening Panthenol and Biotin help stimulate hair growth to restore thinning, weak hair while fortifying Vitamins A, C and E nourish the entire hair shaft for improved volume with fewer fly-aways and split ends. Your hair looks fuller and shinier, and feels thicker and softer. Vegetarian.