To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. It also analyses reviews to verify trustworthiness.
I bought a few Paul Mitchell products on Amazon and from certain vendors it's fine, certain vendors it's not. It's honestly the same price as Ulta where I live and there is no gamble with the legitimacy, product expiration, or manufacturing location by just going there and purchasing instead.