What 'works' has to mean
In Great Britain a health claim may only be used if it appears on the official nutrition and health claims register. That register is the most useful shortcut a shopper has, because it separates nutrients that have been assessed from ingredients that have merely been marketed.
So when we say something 'works', we mean it either has an authorised claim behind it, or it corrects a shortfall you actually have. Those are the two honest versions of the word. Everything else is a hypothesis being sold at a premium.
