Silk Protein and Collagen Treatment by Dr. Therapy. Main Ingredients: A blend of seaweed extract, macadamia seed oil, collagen, and plant protein. Benefits: It straightens hair, reduces volume, and provides deep hydration and nourishment for the hair. Formaldehyde-Free: The product is completely free of formaldehyde at 100%. Usage: Designed for professional use, and comes in a weight of 1 kg (1000 ml). Safe to Use: Developed to be safe for both the client and the professional, it does not emit unpleasant odors or smoke during use.