Can breast still develop in a person who has already complete puberty for several years by administering exogenous estrogen?

This is a condition whereby a woman's body does not produce estrogen, or not enough to building normal female attributes; reverse in men where it is a problem with male hormone.

How old are you ?

Estrogen is actually a 'blanket' term and is not just one hormone but three, as follows:

• Estrone (approximately 10-20% of circulating estrogens)

• Estradiol (approximately 10-20% of circulating estrogens)

• Estriol (approximately 60-80% of circulating estrogens)

Your question regarding exogenous estrogen is highly clinical and complicated as you can see; is your doctor suggesting you take hormone replacement therapy to correct your problem?