That must be terrible for you to have had an itchy scalp for 4 years! I'm so sorry that you are going through that! I used to have an itchy scalp until one time I used Dawn dishwashing detergent, the blue one, to wash my hair when I ran out of money and shampoo at the same time. My itchiness started to go away! So I continued to use Dawn dishwashing detergent. Finally the itchiness went completely away and has never returned. That was 40 years ago. I am currently 80 and still don't have gray hair. I don't know if that is related to Dawn but it's nice.

Shampoos these days are full of junk and have strong scents. That could cause irritation and itchiness. Dawn is very natural and clean. It's also cheaper than shampoos and it cleans your dishes very well too.

I hope this helps. I wish you the best.
PML