I can not answer the question on propecia, but I have something that may help. My wife had her hair fall out and went nearly bald for many years. When MSM came out she started on a quarter teaspoon and worked up to a teaspoon a day. It is also good for the skin, and many things if you body is short on natural sulfur. It is not that expensive if you buy it by the pound or more. It will not hurt you but can cause a detox situation in some people. If so lower the amount and continue.
She tried many natural things that did not work. The MSM not only let her hair regrow but helped in many other areas.
I tried it and unfortunately it caused headaches that did not subside with time. I am the exception though. It has a reputation for being safe. Start slowly and work up. She may experience some discomfort (headache ect) from a detoxing but should subside. You should do a little research first. (Curezone, Google ect.)
Good Luck, If you try it I would be interested in the results.