From some reading I did this morning, 1,3-Dimethylamylamine is a vasoconstrictor, and vasoconstriction can be a contributing factor to ED due to restricting bloodflow. Although none of us have ED, I do think this would tend to explain why we're experiencing less than 100% full erections. I agree with snagency that it's not wise to make a blanket statement about the proudct, as everyone will react differently, but I do think it's worth noting that three of us taking OEP are all experiencing the same thing.