However, all regular selenium-enriched products will issue authoritative selenium content test reports as evidence. You just need to see if the manufacturer provides the relevant test report. Like a selenium-enriched cup, it is necessary to provide a selenium content test report issued by a testing institution with CMA qualification. As we all know, cups are used to drink water. The content of this report must be how much selenium content can be reached in the water after it is poured into the cup in a certain period of time. Only such a cup can be called a real selenium-enriched cup.