I have had seborrheic dermatitis for my entire life and have tried every single type of dandruff and dry skin shampoo that is out there to try to help me. With my dermatitis if I scratched my head it would really look like I would have snow coming out of my hair, it peels so bad and flakes off. My doctor recommended this shampoo and it was really hard for me to find, I had to order it offline, so that is probably the only flaw that there is with it. I used this product for about two weeks before I noticed any results but then it was just a complete 180 degree change, my head did not itch anymore and the dermatitis was almost completely gone! I now use this shampoo twice every week to keep my condition at bay, and sometimes three times if it is getting bad again. It works very well and keeps my head from itching. I do warn you that it has a horrible smell and that part of it is not nice, so I wash my hair a second time with good smelling shampoo after, but even with a bad smell, since it works so well it is worth it.