There are more than 90,000 vitamin and dietary supplement products sold in the US. They come in pills, powders, drinks, and bars. And they all anticipate some better versions of ourselves—selves with sturdier bones, slimmer waist lines, heftier muscles, happier intestines, better sex lives, and more potent noggins. They foretell of diseases dodged and aging outrun.

On the whole, we believe them. Supplements are a $30 billion industry in the US. Recent surveys suggest that 52 percent of Americans take at least one supplement—and 10 percent take four or more. But should we? Are we healthier, smarter, stronger, or in any way better off because of these daily doses?

The answer is likely no. Most supplements have little to no data to suggest that they’re effective, let alone safe. They’re often backed by tenuous studies in rodents and petri dishes or tiny batches of people. And the industry is rife with hype and wishful thinking—even the evidence for multivitamins isn’t solid. There are also outright deadly scams. What’s more, the industry operates with virtually no oversight.