Let's share the proper shampooing method to prevent hair loss.

First, do not use hot water when shampooing. It is better for your scalp to shampoo with lukewarm water.
While washing your hair with hot water is effective for removing sebum and impurities, it can easily dry out the scalp and cause further irritation. In severe cases, it can lead to persistent dermatitis and worsen hair loss in the affected areas. If you have any scalp issues, please remember to wash your hair with lukewarm water.
 
Second, do not rub your hair too vigorously. Friction occurs more easily when wet than when dry. This is because rubbing your hair too hard can irritate the scalp and cause dermatitis. When washing your hair, it is best to wash it gently with your fingertips, as if massaging it.
 
Third, and this is really important, do not wash your hair immediately after shampooing; give it sufficient time.
There are cases where people rinse and dry their hair in just 5 seconds, or less than 10 seconds, after shampooing. Doing so may result in insufficient time for the surfactants in the shampoo to penetrate the sebum on the scalp. Additionally, it reduces the time available for the ingredients in functional shampoos to perform their functions.
Surfactants remove sebum, and a suitable amount of time is required for the ingredients in functional products to perform their functions. While there is no set time, roughly the time it takes to lather the shampoo, brush your teeth, rinse your mouth, and then remove the shampoo is sufficient.