I'm not really a fan of meth, but I've done it before. On one occasion, a friend of my fiance brought some over to smoke with us. I wound up taking morphine in hopes that it would dull its effects with no avail. My fiance and I tried to put all that excess energy to use by having an all-night fuckathon. Neither one of us could get eachother off, so we wound up trying to get ourselves off by watching porn on separate computers. Didn't help. Neither one of us got off, we didn't get any sleep, and we felt like shit when we went to work the following morning. We vowed never to do meth from that point forward. To this day, we've stuck by that promise and we don't miss it one bit (we didn't really care for meth to begin with anyway and I'm glad we never wasted a cent on it). So that being said, yeah, I can totally see it giving people issues achieving orgasm.