Ingredient and functional claims

In the USA, the Food and Drug Administration (FDA) mandates that shampoo containers accurately list ingredients on the products container. The government further regulates what shampoo manufacturers can and cannot claim as any associated benefit. Shampoo producers often use these regulations to challenge marketing claims made by competitors, helping to enforce these regulations. While the claims may be substantiated however, the testing methods and details of such claims are not as straightforward. For example, many products are purported to protect hair from damage due to ultraviolet radiation. While the ingredient responsible for this protection does block UV, it is not often present in a high enough concentration to be effective.