I would like to point out, yet again, that mixed in marijuana does not burn at the heat that the leaves burn, so fentanyl poisoning from smoking pot is highly unlikely.
That being said, anything that is taken in pill form can contain fentanyl, and there is a very good chance that any cheap illegally sold opiates have fentanyl, and the people who add fentanyl don’t care much to make sure that the dose isn’t lethal. All cheap illegally sold psychoactive drugs in pill for can have it, bust since it’s an opioid, it is generally added to other opioids to increase their effects.