What is a potential risk of using shampoo that contains keratin protein?

Using shampoo that contains keratin protein can potentially lead to dryness and breakage, especially if the client's hair does not require the additional strength that keratin offers. Keratin is a structural protein that enhances the hair's resilience and strength; however, when used on hair that is already healthy and strong, it can create an imbalance. This imbalance occurs when the hair absorbs too much protein, making it rigid and less flexible. As a result, the hair may become prone to dryness because excessive protein can lead to a lack of moisture retention, ultimately resulting in breakage. It is essential to match hair care products with the specific needs of the hair to prevent such adverse effects.

The other options do not accurately reflect common risks associated with keratin shampoos. While excessive shine could be a concern for some products, it is not a direct risk of keratin. Additionally, keratin itself does not typically alter the natural color of hair nor is it commonly associated with increased scalp irritation; these are more likely linked to other types of ingredients or individual sensitivities.