Makes you drowsy. Take one pill before going to sleep and you will see a room with the man in blue and you sitting in sofas. If you are out of ammo, you will receive twenty-one after waking up.
Blue Pills can also be traded for 10 bullets each through Hank in the gun shop.
If the player takes six or more blue pills, "You" will begin to remark about his dependency on the blue pills upon waking.