May not be suitable for Bleached or colored blonde hair as it may alter the color a bit however there is a way to avoid it by reducing the heat (Instructions inside). Or Look for INVERTO ONE Or INVERTO 60 for Blonde Hair. Discover the beautiful hair you had all along and wake up with beautiful hair everyday with the Original Formula Keratin Treatment by Keratin Research. Save yourself the countless hours and damage of blow dryers and hair straighteners with the Keratin Research Original Formula Keratin Treatment. Advanced yet fast and simple to use keratin treatment that instantly straightens, smooths, repairs, conditions, and strengthens the hair using an intense conditioning remedy which restores vitality by repairing the hair from the inside out. The amazing results will leave hair elastic, flexible, and soft with a naturally vibrant shine. This Keratin Research straightening Treatment is designed to straighten hair, remove frizz, and add shine, silkiness and softness to your hair. The results are instant! Nothing else to do! The Keratin Research Original Formula Treatment will last for over 3 months and in some cases as long as 9 months. In your current busy lifestyle, you will find this keratin hair treatment by Keratin Research to be a life changing experience! With Keratin Research's Original Formula Keratin Hair Treatment your hair will be easier to manage and maintain, smooth, fast-drying and easy to style. The Keratin Research Original Formula Keratin Hair Treatment is suitable for virgin, colored, and previously chemically-treated hair. INGREDIENTS Hydrolyzed keratin, Keratin Amino acids, Argan oil, Coconut oil, Keratin Proteins and moreMay not be suitable for Bleached or colored blonde hair as it may alter the color a bit however there is a way to avoid it by reducing the heat (Instructions inside). Or Look for INVERTO ONE Or INVERTO 60 for Blonde Hair. For very long hair and/or course and dry hair (dry and thick hair absorbs more product), please consider the 10oz (300ml) version. You want to be sure you don't run out of product in the middle of the treatment. Most people finds 120ml adequate. This Keratin Hair Treatment contains Argan oil, coconut oils, proteins and amino acid complexes for powerful moisture binding for healthy and shiny hair. On your next keratin hair treatment insist on Keratin Research products, nothing works as good. The amazing results will leave hair elastic, flexible, and soft with a naturally vibrant shine. Keratin Research's Original Formula straightens and smooths your hair for 4-6 months. No Need to wait 3 days- Express formula. NOT THE USA VERSION. THIS IS UK-EU VERSION FORMALDEHYDE-FREE VERSION: Advanced yet fast and simple to use keratin treatment that instantly straightens, smooths, repairs, conditions, and strengthens the hair using an intense conditioning remedy which restores vitality by repairing the hair from the inside out.