Is penis shrinkage real?

I just wanted to ask if it is true that finasteride can cause penile shrinkage? My gf has been complaining that my hog is too large and I was wondering if taking it might at least diminish the girth. I have a problem with this claim. You know when you are not sexually excited, the penis is often smallest as it shrinks down. In cold it shrinks as well. Try swimming and it will shrink.

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