I know drug dealing will be added sometime in the future, so I wanted to share some drug efects suggestions (based of the real life efects of these drugs)
LSD (also known as acid): Alucinations (strong visual efects such as heavy screen wobling, weird colors, twisted screen etc)
Ecstasy (also known as MDMA, candy, sweets): Stimulant, so bigger sprint speed and stamina (and maybe some light visual efects due to the "hapiness" efect this drug gives)
Meth (also known as speed, crystal): Similar efects as ecstasy, but stronger (but more prone to illness/overdose) and maybe add a special screen shaking, like the one you get in GTA V when you are about to become sober.
Marihuana (also known as weed, grass): Relaxing efects (like slower sprint speed, and some light visuals efects like some screen wobling etc) but with a heath regen feature to make it usefull.
Heroin (also known as horse, hero): Since it derives from morphine, maybe a good health boost
Cocaine (also known as coke, snow, powder): This drug can cause anxiety and anger, so maybe a strong meele damage boost and a slight health boost
Crack Cocaine (also known as crack, rock, gravel): A derivative of cocaine, so maybe even stronger efects (but a bigger risk of illness/overdose) and the same shaking effect of meth
To prevent rich players (and poor junkies) from buying and consuming bricks of drugs, maybe add a risk of illness and overdose.
There is always a risk of illness, but it starts small, and the more doses the player takes in a short time the bigger risk it has in becomign ill.
If the player takes too many drugs on a short time, it may just die of an overdose (unless a medic is present to treat him, but the drug efects dissapear once treated)
The "bad" side efects could be based on the strenght of the drug, like lighter drugs such as MDMA and Weed being less risky, and stronger drugs such as coke and meth having a bigger risk.
It could also be related to the quality of drugs, as lower quality drugs being riskier but cheaper, and vice-versa.
EDIT
Also, what about being able to mix drugs with drugs or drugs with alcohol in order to get a mixed efect? Like hero and meth to become a physical monster like Brucie, or alcohol and LSD to double the fun. But again, in order to prevent people from taking lots of diferent drugs and becoming essencially super-soldiers, make it so if you mix drugs with drugs or drugs with alcohol you run a very serious (45-65%) risk of overdose, even if you only take one dose of each. This will make people seriously think if they should risk taking these to become unstopable and then go straight to the hospital.
