I suggest you ask for a bio-identical cream. The pills are are usually similar to the human hormone but not the same.

Did you find any research about using progesterone this long after the concussion ? What I have read referred to using it immediately after the injury while the brain is still struggling to save or protect the injured brain cells. It protects from damage but does not cause healing from what I read.

I highly encourage you to seek out a specialist in bio-identical hormones. I speak from experience as I have watched my wife's success when she found a good specialist.