I'm a 55 year old male who has a breast size of 44A. I'm thinking about going on estrogen to get to a size of 44C or 44D.

Thank you for your question. I would recommend seeing a board certified plastic surgeon for an in-person consultation. This way, you can express your concerns and discuss all your options. 

Far more important than the technique is the skill and experience of your plastic surgeon. Choose your surgeon rather than the technique and let them explain why one technique may be better than another.  See the below link on some suggestions on finding the most qualified Plastic Surgeon for a Breast Augmentation Always insist on a board certified plastic surgeon.

Thank you for the question.   Sorry but it is impossible to predict exactly how much your breasts will grow with estrogen therapy.  Having said that, some of my transgender patients have been able to achieve a C cup;  I have yet to see a patient achieve a  D cup based on estrogen therapy.Best wishes.