Who came up with Propecia having sexual side effects in the first place?

[PatientlyWaiting]

I have been taking generic fin for 7 months, maintained and regrew some hair on the vertex, hairline stopped receding. So far so good, no sexual side effects.

What I want to know is, if fin side effects is all in the mind, then why does Propecia warn users about sexual side effects? What made them warn users about this, was it determined in the clinical trials before Propecia ever came out?


It makes no sense to me, if it's all in your imagination, then why did Propecia warn users about the side effects? Is it basically Propecia's fault, that many men suffer mentally from fin thinking that they have sexual side effects because Propecia is the one causing this imagination by telling to beware of those side effects, or are sexual side effects actually scientifically real and that is the reason why Propecia warned us about it in the first place?


If Propecia had instead invented a different side effect, like "Numbness in pinky finger may occur in 2% of men"[it's just a random example], would Propecia users be claiming they have numbness in their pinky finger, even though the drug really doesn't cause numbness in the pinky finger?