Difficult question.
Hair loss depends on genetics and environment.
We can not do so much on genetics, but can delay hair loss process.
If you use shampoo, then you should rinse your hair with water for at least 3 minutes after applying shampoo. This will clear away residuals of shampoo that can cause hair loss.
If you indeed worry about that, you may visit any office of dermatologist.
Barbie~~