Alternative viewpoint
So rather than Les being enrolled on a drug trial, what do you guys think about the whole movie being an acute psychotic episode, possibility triggered by cannabis use (we know a few of his friends partake).
All of his interactions with the doc that recruited him feel unreal, maybe the only clear moment was when he returned to the offices with his friends and the doc didn't recognise him. I know Les had pills and the green liquid treatment given to him at this point, but all scenes with these items in could be delusions too.
The scene that really got me thinking was before Les got beaten up by the invisible suits... The resulting injuries, together with the lights, approaching horn and corridor style of the buildings just before the confrontation gave me the impression Les might actually have been on a railway line and was hit by a train. The suits didn't exist at all...
Any thoughts?