I recommend Dr. Twenty hair loss shampoo.

I was born with thin hair, and it has been getting even thinner. The crown of my head also feels sparse, and I noticed a significant increase in hair loss, so I urgently purchased this. I roughly compared the amount of hair falling out every time I washed my hair for a few days, and since the shedding definitely decreased, I have been using it with confidence ever since. The cooling sensation typical of anti-hair loss shampoos is slightly less intense, but I actually think the scent is better. It is also great that it lathers richly even on oily hair, so I don't have to squeeze out much.