Surgery can be scary for many people and it is very common to seek non-surgical alternatives. With regard to breast reduction, some women will notice a decrease in breast size, but may also find that their breast sags more after significant weight loss.
In general, if your breasts are significantly enlarged and you would like them smaller, the best results will be obtained with breast reduction surgery. I encourage you to explore options with your Board Certified Plastic Surgeon and express concerns you may have about surgery. Best of luck.