For the study, researchers looked at data on E.R. visits from 2004 to 2013 that were linked with dietary supplements. That data revealed that 3,667 people who took dietary supplements and experienced heart problems visited emergency rooms over that time period, which is, um, kind of terrifying.

A majority of those patients were women, and roughly 25 percent of them were between the ages of 20 and 34. Most of the patients reported using only one dietary supplement, too, so it’s not like they were habitual users. The study authors say that a majority of them were meant to aid weight loss or boost energy levels, while others, mostly taken by guys, were marketed for bodybuilding and sexual enhancement.

Though the sample size of this study is pretty large, the lack of info provided by most E.R. patients, like the type of supplement they were taking or if some patients took supplements and never told their physicians, means that the study authors’ estimation could be less than the actual number of supplement-related emergency room visits.

Here’s the thing about these pills: Since the FDA doesn’t regulate them or require them to be tested for safety, there’s really no telling what’s in these potentially dangerous weight-loss aids. Earlier this year, another study found that many herbal supplements are 100 percent phony.

The takeaway here? The risks of taking supplements that promise too-good-to-be-true results definitely outweigh the benefits, even if the idea of popping a pill to hit your pounds-dropping goal sooner seems pretty freaking irresistible.