Is it bad to drink yerba mate everyday?

Yerba mate is POSSIBLY UNSAFE when taken in large amounts or for long periods of time. Drinking large amounts of yerba mate (1-2 liters daily) for a long time increases the risk of some types of cancer, including cancer of the esophagus, kidney, stomach, bladder, cervix, prostate, lung, and possibly larynx or mouth.

Why is yerba mate bad for you?

Yerba mate isn't likely to pose a risk for healthy adults who occasionally drink it. However, some studies indicate that people who drink large amounts of yerba mate over long periods may be at increased risk of some types of cancer, such as cancer of the mouth, throat and lungs.