Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
Don't know that it's working to help my hair loss but I love this shampoo anyway. My hair really likes it. Took some getting used to the minty fresh smell. If you're used to using shampoo from the grocery store it will take some getting used to; it doesn't lather up as much because it doesn't contain SLS which is a cheapo product and bad for your hair.