I am on P for quite some time now. Progesterone will not increase your breast growth, it might help to fill your breasts out more, i. e., make them rounder. I don't have seen much of it. I just ran across some research indicating that progesterone is more effective when taken with fatty foods, The practice of taken oral progesterone rectally seems to have no benefit if the P is not specially formulated for this. In that case it can also be taken vaginally, which is less messy. Otherwise the oral stuff should be taken with fatty foods for maximum benefits. I did not do that, and will start to make sure I do it in the future.
Hugs
Linde