Final answer:
Protein shampoo deposits protein fragments along the hair shaft, helping to strengthen and repair damaged hair through ingredients like keratin.
Step-by-step explanation:
The shampoo product that deposits protein fragments along the hair shaft is known as Protein shampoo. Protein shampoos are formulated specifically to penetrate the hair shaft and reinforce the hair with protein, which helps to strengthen and repair the hair's structure. Proteins commonly used in such shampoos include keratin, which is a natural component of hair. These types of shampoos are particularly beneficial for hair that is damaged or frequently styled with heat. By depositing protein, they help to rebuild the hair's natural fiber and protect against future damage.