After stuffing ourselves silly over the holidays, it’s time to hit the reset button. For some that means dry January, while others opt for a juice cleanse. Those who preach the juice cleanse gospel will tell you their three-day (or more) liquid diet flushes out all the toxins that have built up in their body. But this video from SciShow calls their bluff. There’s no science to back up these claims—and our liver and kidney do a fine job of getting rid of toxins. While a juice cleanse probably won’t hurt you, it’s not the healthiest choice either.