Many of the dangers with drug use aren't the actual drugs themselves, but the environment, the dirty needles, and the cutting agents in the drugs. Many long term heroin users end up dying of liver disease, not because of the heroin, but the cutting agents. Many users end up sharing needles and contracting diseases like Hep C and HIV which wreck havoc on health care costs. Having safe injection facilities can cut down on overdose deaths and diseases acquired from dirty needles. No policy or education will completely eliminate drug use, but we can make people's lives easier who go down that road and potentially make it less stigmatizing and easier to get help.
We have survived and lived and especially thrived off of drugs, it just becomes criminalized because there's still feudalistic remnants of social unacceptability and no modern research into positive consumption of drugs in general, so until that changes for the better, we have a war on terror, war on drugs, war on the battle of the sexes, mental health crises' and especially coming out as a poly-substance user, I think it's healthy if it resolves issues in your mind and you can have fun and creativity can spark from it especially within the realm of science where psychopharmacology is governed by financial regulations limiting and moderating the initial epistemological research necessary for the research of drug consumption with safe and affective, not effective use.
Prison doesn't work, rehab only works for some people, and others can't afford any treatment at all. The very least we can do is acknowledge that there are going to be users and make sure they are doing their drugs safely. This also prevents non-drug users from communicable diseases spread by unsafe drug users.
Addicts have family too and I'm sure there family would rather have them take drugs in hygienic and controlled conditions rather than in some hole in the wall. Also, I think in the proper environments, addicts can cut back and eventually be free of drugs. Denmark is on the right track with this initiative.
I know prison is not effective when it comes to drug charges but come on... Really? Allowing addicts to take drugs is NOT productive. True, it may help prevent medical issues related to drugs, but we won't see any actual decrease in usage of drugs. And using drugs is the real danger.
No, addicts should not be allowed to use drugs under supervision. There is no reason anyone should be condoning the use of drugs in any situation. Doing this would be sending these addicts the message that what they are doing is acceptable, and that is just not the case at all.
They could overreact because the drug might make them go crazy and make them attack the person who is watching them. If that happens nobody might notice because they could do it silently and then the supervisor would be missing and the addict would be killed and they would've never even improved their health.
Watching people use drugs does nothing to solve the problem. It only normalizes the behavior for the people that are using the drugs. It tells them that there is no need for them to stop the behavior, even if it is harmful. This is not a way to combat drugs.