It’s purposefully worded that way to be misleading, even to native speakers. Explicitly calling something medicine or a cure means it would have to be tested and regulated. However, labeling something as being for wellness isn’t covered by that, and is just vague enough to have people think positively about it. That’s not saying that there aren’t beneficial things labeled under wellness; roughly speaking though, it’s can be used to sell whatever you want, while making people assume it’s actively good for them.