Get intensive care for your weakened & sensitised hair with the Redken Extreme Strength Builder Plus Fortifying Mask Created for those whose hair is very damaged, this rich & pampering mask will replenish its strength, helping you on your way to healthier-looking, more resilient hair. The formula is enriched with Redken's famed Interlock Protein Network (IPN) & Fortifying Complex, which delivers targeted hair to areas of concern. When used weekly, the Extreme Strength Builder Plus will help your hair get back to its best, protecting weakened areas & leaving hair feeling much more manageable & supple. Apply to damp hair after shampooing. Leave for 5 to 15 minutes depending on the severity of the damage, then rinse away thoroughly.