I can't say that I've had much luck on either, unfortunately.
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Propecia (Finasteride) even taken at the greater dosage intended for an enlarged prostate didn't effect my hair much. (I've been on it for about a year and a half) If anything, I'm still losing hair gradually.

6 months should be enough to know if it's working for you though.
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I've been on Minoxidil for years, but decided to stop last Spring. I was never really sure that it was working, and considering that I didn't really lose anything after stopping it, it probably wasn't.
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All in all, it's the luck of the draw. If potassium channels are your problem, Minoxidil might help. If T is the problem, Propecia might. Otherwise, could be diet...could be stress...could be exercise...could be something else. I'm still trying to find out what my solution might be.
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I don't know about whether HRT will have any effect, but I am curious as well.