It’s largely reversible in the first six months or so. Generally breast growth is not reversible and for some people that takes a while to start but for some it begins to happen sooner. You could try it for a couple of months and stop if you feel tender nipples, which is a sign of breast growth activity. Though my biggest changes have come a year in to the hormones due to the way they ramp things up over time. I was taking 2mg E per day at the start and now I’m taking 8mg E and 200mg progesterone (which helps suppress testosterone), so my experience now is much stronger than it was a few months in.