I'll give IFM a drug overhaul in a few dot points and fix the entire drug economy and HP issue:
Drug effects don't stack and each drug has a HP cap.
For example, you take cocaine and get +20 HP - AND NO MORE!
The drug effect wears off in 15 minutes - to keep the HP boost you need to take more.
As your addiction level rises, so does your HP cap - i.e. you have a high addiction level so now you gain +25 HP and not +20 HP.
With an upper limit of maybe +30 - obviously we don't want to see junkies with +500 HP.
This promotes more drug use thereby stimulating the drug economy, giving incentive for people to roleplay addicts and removes the drug stacking issue.
I've never played an RPG game that lets you take an item that gives you 200% HP. If World of Warcraft doesn't let you do that, why the hell does a Heavy RP server?
Having used drugs should give you a slight advantage - the ability to take maybe one or two extra bullets (which can be the difference between life and death), not an extra ten.
ALSO:
The idea of "uncutting" cocaine back to pure quality that IFM is toying with is probably the silliest thing I've ever heard. Are we trying to roleplay realistically or just be an arcade game at this point?
Not only does it make zero sense from a sense of realism, is it even financially viable from an OOC standpoint?
Assuming that it's like 2:1 - 1kg of 50% is going to give me 500g of pure.
I'm selling 50% for $175 and pure for $300
1kg of 50% = $175,000 | 500g pure = $150,000
Maybe I have the entire idea behind it wrong or don't have the full picture? But it doesn't make sense to me.