There's an inverted-U graph of approval vs. effect size. Most things with no effect aren't approved. Things with moderate effect are heavily studied until enoug

There's an inverted-U graph of approval vs. effect size. Most things with no effect aren't approved. Things with moderate effect are heavily studied until enough evidence is gathered for approval. Things with huge effect don't get much study, because it's not very exciting. For instance, bottles of vitamin C pills in the US are labeled "This product is not designed to treat or cure any disease", despite everyone knowing that they cure scurvy. I wonder which side of the U flossing is on.