They also scored how soft it felt and to what degree it still felt damaged. Consumer Reports found, regardless of their claims, shampoos alone can t do much to improve damaged hair. If your hair is damaged, the best thing to do is to use a conditioner after you shampoo. That will improve how it looks and feels. Other tests checked shampoos for color-treated hair.
Hair color tends to fade in the sun.
So technicians exposed dyed hair to intense ultra-violet light, to simulate sunlight. Then the tresses were sorted from the least to the most faded. Besides sun-faded tresses, the tests also included hair that had been shampooed repeatedly. That can also cause fading. In the end, the tests found no shampoo did a great job of keeping hair from fading.