If it is invalid, of course, it can be returned. Now websites are all about credibility. A bad brand is as painful as a broken life. However, we must find out the invalidity ourselves. If there is nothing wrong with the product, it must be that we didn't pay attention when taking it, or overeating after taking it, which is definitely ineffective. Of course, if the product itself has quality problems, it can definitely be returned. In short, we need to find out why it is invalid. I suggest you consult their customer service in detail before buying, which is safer.