I started using this about 3 months ago. I had sampled it by applying a couple of drops in my hands and patting it on areas that looked especially crinkled. I often get sores on my scalp, and I can itch them so much during my sleep, or simply when I'm not paying attention, that I lose chunks of hair in those spots. I've used oils and Dr. Miracle's, and Hawaiian Silky, and ORS stuff . While they all definitely help my hair and scalp, they have more of a softening, detangling effect than this Ouidad Serum. When I liked the way this made my hair look less "fluffy" I decided to try putting it on the sensitive areas of my scalp. It is so, so soothing. About 2.5 months ago I decided to apply this nightly to my scalp, especially along the hairline where I always have those fluffy short hairs that never grow and always point in the wrong direction. When used as a light finisher on all my hair, I am certain this prevents breakage. I did not expect topical biotin to cause my hair to grow, but I've got to give this serum credit for doing something! Perhaps it is less breakage, perhaps it is a healthier scalp, but my hair is longer and fuller and curlier than it's been in years. My curls are smaller and tighter, like they were before I started chemically damaging my hair. I have not been getting itchy scalp sores, which certainly helps the hair follicles in those areas, and I don't notice ingrown hairs either. This is yet another Ouidad product that seems so darn expensive, but there doesn't seem to be a cheaper alternative. This is a very light serum that disappears into my scalp. It's not oily at all like typical scalp treatments, and it dries on hair like water, with no residue. It rinses from hair like water as well, if hair need to be wet in the morning. It has a nice, light clean scent and it feels cool. Even though I've been using this regularly, and sometimes in excess of the recommended amount, I'm not even halfway through this bottle. The product is applied with a dropper and you need literally only 3-4 drops at a time. Again, like other Ouidad products, this is so concentrated it winds up lasting much longer than cheaper products in bigger bottles. I've been dealing with those stupid scalp sores my whole life, and they're actually gone. For me this product is truly worth it!