Will propecia help with hair loss resulting from hypo or hyper thyroid? Or does it only work for male pattern baldness?

Brad6137,That is correct Propecia only works in AGA, since it decreases dht this helps male pattern baldness. Remember that AGA, results as the interaction of dht on the hair in the inherited pattern is sensitive to the shortening of the growth phase by dht, hence the hair in this pattern becomes progressively shorter and thinner. Thyroid conditions cause a tlelogen effluvium which is a sycnronizaiton of the follicles to enter into the resting phase at the same time.Sincerely,Bernardino A. Arocha, MD

If a person has androgenic alopecia with thyroid disorder, then Propecia will help. Propecia deals with lowering DHT. DHT is what is causing typical androgenic alopecia.

finasteride is a DHT blocker (blocks the enzyme that makes DHT) which is effective for MPB. However, if you have an underlying thyroid issue, this may exacerbate or speed up MPB, and you should get your thyroid hormones under control which can also help your hair. 

Propecia (Finasteride) will not help regrow hair lost by hypothyroidism. Thyroid hormone replacement will help regrow some of the hair lost however, if hypothyroidism is longstanding before treatment then results will be less.

Propecia (finasteride) works strictly on male pattern balding, but if your thyroid problem accelerated a genetic process then it might be effective