I too tired the pumps while on and off HRT. I loved the results, only issue was they were temporary at best. I used the suction ones, and actual pumps for milk. I will say, while taking milk meds, I did produce small amounts of breast milk. While using the suction pumps, my breasts stayed enlarged for a few hours at most, but where so tender the next few days, do to the amount of suction and the duration I left them on.