If a cop wants you dead so bad he's willing to throw something I presume is worth millions aside for it, such law is the least of your problems.
that itself is another problem. if the system can make it extremely risky to sell such deadly drugs, its price will have to go up significantly, forcing many many people to stop abusing it.
you won't see that many fentanyl deaths if it costs say $10k per gram on the street. sadly, it is dirt cheap now, at only $100-200 per gram, people are dying.