We have all used hair shampoo for the body as well, but if this is what it usually does, you should probably change your routine.

Although it seems like at first glance there are no major problems or changes, the chemical structure of body and hair shampoos has some changes.

Hair and body shampoos usually contain surfactants that mix well with oils and then rinse lightly with water to remove those hangovers. But, they have different ingredients to achieve different goals. Shampoos often contain softener / conditioner to make hair thicker and easier to wash. Even body shampoos have a factor that hydrates the skin, but it is not exactly the same.

Moreover, hair shampoos usually contain lower levels of surfactants compared to those of the body. We usually want to remove less oil in the hair compared to oils in the skin and the higher concentration of surfactant in body shampoos aims to achieve just that.

The idea is that "shampoos are formulated to intentionally leave ingredients in the hair to keep it smooth, while body washes are created to remove any dirt, oil. Furthermore, more acidic shampoos can cause skin irritation. Shampoo is usually formulated to avoid hair shedding from natural oils, but the use of a body shampoo on the hair will leave the skin brittle and dehydrated.

In conclusion, there is no problem if something like this happens to you once, but dermatologists do not always recommend doing it. 

Source: Well & Good