Just judging by my own anecdotal usage of the product I might have an idea. At first, I started using it daily. Gotta block that DHT topically everyday...makes sense, right? Or so I thought, at least. Well, this was before I knew that 2-3 times per week was the recommended usage. After about a month or so of daily usage, my hair was really unhealthy and dry. It seemed almost crunchy in certain parts of my scalp. It's original use was as a dandruff shampoo, so it does tend to have a greater effect on the hair and scalp than regular shampoo.