so potent, the dose the size of a few grains of salt is enough to get high. north dakota's top federal drug prosecutor never heard of them and neither had christian bjerk's parents. >> i had to learn information on it on the internet. i didn't understand the synthetic drug, i didn't know what it was. didn't know how dangerous they were. >> the message we got after we got on the internet, somebody had said it was okay for these drugs to be on the street. and they had been tweaked. but that's all we knew. >> synthetic lsd has been blamed for at least -- >> parents across the country now learning the painful truth about synthetic, designer drugs. >> investigators say he overdosed on synthetic marijuana --