I am really surprised by the negative reviews for this product. A few months ago I was under a lot of stress and for the first time, I started losing A LOT of hair. I was also getting really bad dandruff. I was scared I was going to go bald at that rate. I purchased this shampoo along with the daily scalp stimulating spray. This was the first time I spent so much on a product (normally I get shampoo in the 3-6 dollar range) but I was desperate to stop the hair loss. After using these products, my hair stopped falling out and my hair is now growing back in (i have a lot of 3-4 inch long hairs so i can tell that it's new growth). I can't say for sure whether they actually helped stop the hair loss + hair regrowth, or it wouldve grown back anyway if I hadn't used them (the only way I'd know is if I used them on half of my head and the other half continued to use my normal shampoo I'd been using). My gut feeling is that they did help. However, I've decided to repurchase this shampoo even though it's so expensive because I think it's really good quality anyway and it certainly isn't hurting me. My dandruff has gone away, too. What I like about this shampoo is that it doesn't build up or weight down my hair. Normally I have to rotate my products to avoid my hair looking greasy and limp but I've been using just this shampoo for a few months straight any my hair is still voluminous and clean looking, and I don't think I've ever liked a shampoo enough to repurchase. If you use a lot of shampoo fast then this would probably be too expensive to keep repurchasing but I have very fine hair so I don't use much product at once (this bottle lasted me about 6 months shampooing every other day). I am so pleased with this brand that I have started purchasing other products from them.