Is there any treatment or research on one to mitigate the side effect of proscar (finasteride) that is said to permanently damage a healthy libido?

Temporary. The decreased libido side effect is reversible several monts after you discontinue the drug.
Libido. There is absolutely no side effect of Proscar (finasteride) that can permanently damage libido. Actually on a theoretical basis, libido should improve as small rises in testosterone may occur with proscar (finasteride). The halflife of Proscar (finasteride) is very short so the effects of the drug are out of your system in less than a week. Another wives' tale debunked.