We proudly stand behind our products and quality controls. If you are not 100% satisfied with NeuroQ, you may return the product (opened or unopened) within 90 days of receiving it for a full refund (less s&h). Please note that because we are unable to control the quality of our products sold by other sellers unless otherwise prohibited by law, the Guarantee is not available for products purchased from other sellers. The Guarantee is also limited to the original, end-user purchaser.