High doses could elevate heart rate to dangerous levels, and even cause heart attacks, it was banned by the Federal Drug Administration.

One of the theories about how hoodia works is that it tricks the brain into thinking that it has enough blood sugar. Without proper feedback regulation, it’s possible that a person’s blood sugar could drop dangerously low while taking hoodia. And with the regular hunger mechanism turned off, the normal warning signs may be suppressed, until it’s too late.