My prolactin went way up when I started HRT, but stress may have been a contributory factor (acute PTSD onset). And when I got taken off anti-androgens for a couple of months (against my better judgement) it dropped down again. I'm getting some new results tomorrow now that I'm on anti-androgens again, it'll be interesting to see where the prolactin is at.
It never went above 700, and my doc said they don't worry until it goes over 1000 (I'll look up what units this is in later on and add that here, we use a different schema in the UK from the US for hormone etc. measurements).