That's all I remember about the premise.

There was a scene very early on of a character (MC or related) sitting in the reception hall of the company or university or such.

Maybe he was thinking about what it could be like to take that drug and stay under watch for basically the rest of his life? Or something like that.

Art style seemed a bit old. Not too polished. Something like Monster but less smooth.

Possibly (really not sure yet): Eternal Sabbath