If a Male Applied Estrogen Cream Directly to the Breasts on a Regular Basis, Would It Increase Size?

While I am not an endocrinologist, I do lecture to many transgender individuals around the country regarding breast augmentation.  I even had an endocrinologist specializing in transgender endocrinology practice in my office twice monthly for years.  I would refer to his recommendation to staying away from oral estrogen and rather use injectable estrogen or even pellets.  I would definitely refer to your physician regarding this topic.  Regarding applying cream to your breasts and expect them to grow, you may have some increase in size depending on how much estrogen gets absorbed through the skin.  It doesn't have to be applied to your breasts though.  I have seen a number of transgender individuals use estrogen patches with good success. 

No OTC medicine increases breast size in Men ! Stay away from supplements that claim that they can do this- it is a scam. If it worked it would have been tested and FDA approved for this usage. The only medicine that might work would be for male breast enlargement caused by an endocrine disorder. You would need to see an endocrinologist for a work up if this involves you. 

No prescription breast creams generally do not work and can be dangerous.  However, transdermal estrogen is a possibility for hormone therapy.  Your endocrinologist will determine the best way to administer the estrogen.  I don't think that rubbing it into the breast will do anything more than delivering through the skin elsewhere.  

It would be best to check with an endocrinologist, but the cream will likely not result in an increase in breast size. 

No you'd be wasting your time and risking blood clots. If you are serious about the MTF transformation, you need breast implants.