I think this applies to females and males but I've heard illegal drugs can really reduce libido.I do NOT condone using illegal drugs of any kind.
I do remember being told me that certain meds can as well. Not sure what meds will but it could be a libido killer.
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*Midori Gurin voice* I'm that one random Alice in Chains (mainly Sean and Jerry...Okay all of them.) fangirl mixed with other fangirl type stuff or nah...Okay, I am.
*goes back on phone thinking of first cosplay ideas*