I'm using 80 to 120 mcg per shot; normally 120mcg. Keep in mind I have seen people, with
no opiate tolerance, use 2,000mcg (which is 2mg) IV for a "recreational high" that they wanted to repeat in a half hour (

). I can feel good from a single 120mcg shot.
I take it that I'm extremely sensitive to drugs in general, especially psychedelics and opiates.
I also can go quite a long time in between shots with withdrawal symptoms (yawning, watery eyes/nose, some cold chills/goose bumps) without it bothering me that much, which enables me to get a lot out of each dosage instead of just maintaining normality.
By the end of some nights I'm definitely nodding on buprenorphine, and on average I only use four shots a day, which is a bit short of 0.5mg a day.