Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great Product

I have been using Spiru-tein for over a year and a half now. My nails grow like crazy, and there is hair growing in other areas that was not there before. I have to shave more, which was not why I brought the product. It was mainly to get my thinning hair on my head to grow. Maybe I'm using too much, but it says a cup. It has definitely helped my thinning hair to grow. So I would continue buying this product as long as it is on the market.