And as CBS News Correspondent Sharyl Attkisson reports, many believe that "all natural" means "always safe."
That's what Caroll Radford thought. She'd just gotten a clean bill of health from doctors. But hoping to ward off winter colds, she tried a natural supplement touted as an amazing immune booster -- Yew Tree Tea. She drank a cup every day for two weeks and then had a seizure. Four weeks later, she was dead.
What Dan Ruby, Radford's son, wants to know is, "Why isn't there a warning label on there bright red?"
Radford's family and doctors suspected the Yew Tree, which is long known in the medical community, as it turns out, for its poisonous potential.
Ruby wants the label, "so that you'd take a look at it and say okay, well I don't think I wanna take it."
But warnings aren't required for any dietary supplements. They don't have to be proven safe or effective. And there are no purity standards.
It's all due to a 1994 law pushed through by the industry. It officially defines supplements as "foods" not "drugs", exempting them from nearly any and all federal scrutiny.
Since the government doesn't treat supplements like drugs, many consumers don't either. But there are countless risks. Some may inhibit blood clotting. St. John's Wort may negate birth control pills while Melatonin has been linked to seizures in children.
But it's nearly impossible to yank bad supplements off the market, says pharmacologist and FDA consultant Dr. Raymond Woosle.
While drugs must be proven "unsafe", supplements have to be proven dangerous.
Woosley explains, "It's much easier to prove a product is unsafe, than it is to prove that a rare reaction, beyond a shadow of a doubt, is harmful."
One reason getting proof is so hard, is that supplement makers don't have to report adverse events. For years, the FDA tried to get Metabolife to turn over health complaints it got about its popular Ephedra products. When it finally did, there were 13,000 of them.
Now Metabolife is under criminal investigation because the company's president had stated earlier there hadn't been a single complaint of serious illness.
Supplement makers insist the dangers are overblown. But some are now embracing the idea of stricter laws, as long as they can help shape them.
Wes Siegner, dietary supplement industry representative and member of the Ephedra Education Council says, "Industry is very supportive of regulation of these products and we've been trying to work with FDA for years to get reasonable regulations."
But Radford's son wants to get the word out any way he can.
Says Ruby, "Whenever I tell my story to people they say it's a tea. If it's a tea it has to be good for you, an herbal tea it's gotta be great for ya."
His message, whether it's a tonic a pill or a tea, even if it's all natural, it can still pose a great risk.