One of the most popular cholesterol-lowering supplements available in the U.S., niacin, might actually be doing more harm than good.

"For every 200 patients we are treating with niacin, it is possible we are causing one excess death related to the drug, and that, for me, is a level of toxicity that is just not acceptable." (Via WPTV)

Two studies published in the New England Journal of Medicine examined niacin, also known as vitamin B3. One looked at extended-release niacin, and the other looked at the combination of niacin with laropiprant.

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Neither found significant benefits to niacin. Instead, the studies show sie affectsa increased adverse effects such as bleeding, stomach ulcers, heartburn and diarrhea, as well as a 32 percent increase in diabetes and a 9 percent increase in death risk. (Via e-Magine Art / CC by 2.0)

Niacin is intended to lower bad cholesterol and raise good cholesterol, and while it accomplishes both of those, the study found it doesn't actually reduce risk of stroke, heart attack or chest pain.

It wasn't all that long ago that institutions like the Mayo Clinic and the University of California-Berkeley were praising niacin's cholesterol-lowering abilities.

LiveScience reports niacin use has nearly tripled over the last eight years and the U.S. spends more than $900 million on it annually.

But then health care professionals began questioning its use after a study in 2011 found patients taking niacin had strokes more often than those who didn't. And now many are calling for doctors to halt its use entirely. (Via National Heart, Lung, and Blood Institute)

In an editorial published alongside the new studies, one doctor wrote: "On the basis of the weight of available evidence showing net clinical harm, niacin must be considered to have an unacceptable toxicity profile for the majority of patients and it should not be used routinely."

That official did go on to say that it could be helpful for patients at a "very high risk for cardiovascular events" who have complications with other supplements, but that's a decision doctors and patients should make carefully.