They cut drugs with various substances to increase volume and / or perceived strength, and that can cause health issues just as dangerous or even death by accidental overdose. In fact the number of overdose deaths have increased in Portugal since that policy has been implemented. Another flaw of this policy is that when users don't have to spend money on paraphernalia, they will have more money to spend on drugs. So I would say this is not about safety of the consumers, but to protect Portugal's healthcare system. It is easier and cheaper to deal with a dead overdosed consumer than a consumer who caught HIV.
> They cut drugs with various substances to increase volume and / or perceived strength, and that can cause health issues just as dangerous or even death by accidental overdose.
This is true, but you're saying something different than what you started off saying.
I agree with you that the government should be supplying heroin to addicts, and if you're decriminalizing drug usage, there's no reason that you shouldn't be doing this. A doctor having the ability to monitor addicts under their care would give us the means to keep them happy and productive, and to make sure they can get off the drug when they're willing to risk the effort.
Many people who take drugs lead happy and productive life and use them as a tool and this approach doesn't seem to address why people reach for drugs in the first place. That's why I believe this policy is dishonest.