One of America’s most popular doctors, Dr. Oz, was recently at a Senate hearing over his recent showcasing of dietary supplements on his incredibly influential daytime show. John Oliver and Last Week Tonight dug a little deeper into what’s wrong with that and made it sharply funny as well, which has really been their niché. Educating the public as they get to do longer segments on HBO and then getting to do much bigger jokes, gags, and bits, again, because they get 30 min. as opposed to 22.

Watch the segment here and make sure you check your dietary supplements twice, if you do that sort of thing, even after they’re recommended by Dr. Oz.