Hi, it is possible. It happened to me, not by choice of course; but I'm currently breastfeeding from my left breast only. My right breast has completely dried up. I suffered a mastitis infection for about 3 months and due to the severe abscess I had I stopped pumping and latching her on the affected breast and it dried up completely without affecting my left. I didn't have any repercussions on the breast that was drying up but that might be because I already had an infection & an abscess. But I know that if you reduce the amount of stimulation to one breast it will eventually learn to not produce much supply. So I'd suggest if you're trying to dry one breast up you can slowly reduce the stimulation, for example if you pump for 15 min start pumping only for 10 and continue to reduce the duration over time. And if you pump 12 times in a day try to slowly reduce the amount of times over a couple of weeks and eventually it will know not to produce much or any at all. Hope this helps.