that sales were halted. >> a new stimulant called ephedra. >> narrator: by then, more than 160 deaths had been linked to the supplement. >> it almost takes a sacrificial lamb to die of liver injury or some other injury before the food and drug administration can take any action. >> hi, i'm dr. bonkovsky, thanks for being here. >> narrator: dr. herbert bonkovsky is an investigator with a liver injury network funded by the national institutes of health. >> let me get a listen of your lungs... >> narrator: he's concerned about the harm supplements are causing. >> just lie down. this has been sort of the fastest growing kind of liver injury that we're observing in the drug-induced liver injury network. the frequency with which we see this has roughly tripled in the last ten years. about 7% of all the cases that we've enrolled into this network over the years were due to these. in the last couple of years, it's been around 20%. >> it's incredibly hard to quantify the current problem, how much harm are supplements doing. just yesterday, i was talking to a patient who suffered a bleeding str