I think it's okay that, as the donor, you want some reassurance that they won't spend all your money on drugs. They have a choice to not accept your donation.
Ideally it would be a combination of money and food.
You don't need reassurances about how the money will be used. Part of it may be used for drugs. But if a drug user is self-destructive enough to buy only drugs and no food, he or she would probably just take an overdose anyway.
As a case in point, Norway's social safety net provides a living wage to anyone who can't provide for themselves. This involves a lot of drug users. They do end up spending some of the money on drugs, but at least they don't starve or freeze to death. I think this is a tradeoff that's worth it. You both save the effort of micromanaging and provide some dignity to people who have too little of it. If someone wants to be self-destructive, they will be regardless of the circumstances.
As a case in point, Norway's social safety net provides a living wage to anyone who can't provide for themselves. This involves a lot of drug users. They do end up spending some of the money on drugs, but at least they don't starve or freeze to death. I think this is a tradeoff that's worth it. You both save the effort of micromanaging and provide some dignity to people who have too little of it. If someone wants to be self-destructive, they will be regardless of the circumstances.