Of course, it's better to be attentive when buying something online but there are not so many scams as it seems. A reliable online pharmacy can't have bad reviews, so don't forget to check it. I buy all pills, vitamins, and supplements at Canadian Pharmacy Online.
I have purchased curcumin from Ebay. Well it seems to be okay,it didn't poisoned me although you cannot be 100% sure what's inside.
I only trust that FDA had regulation control on the company which made this product.