I had a super long post typed out about my life-story, but I'm just going to say the following: I am pre-med and I believe the following info to be relevant and useful to a certain poplulation of this site. Premature ejaculation? Unsustainable erections? Serious apathy and performance anxiety in the bedroom and elsewhere? No sex drive? Penis losing it's "muscular" and rigid appearance aka atrophy? Depressed? General agitation in the bedroom? Loss of sensation and sensitivity? Don't get that sexual urge in the pants with visual stimulation? Definitely give a magnesium (not oxide, try glycinate or taurate) supplement a shot. I have been lead on before thinking that I have had vitamin or mineral deficiencies in the past, but after at least 10 years, this is the answer for me and to the above questions. I'm just happy it was discovered at a semi-young age of 31. More than 50% of the US population doesn't get enough of it, even if eating a well balanced diet and especially if you are any sort of athlete. Don't count on a blood test or a doctor being able to reveal a mg deficiency. Only 1% is found in blood- the rest is in organs, tissue, and cells. Usually discovered after death by autopsy if lucky. If you have 3 or more of the common sypmtoms it's very safe to assume that you are at least slightly deficient. Assuming you've consulted a doc first and have not found a solution, try it and get back to me. It saved me in several different capacities, and if it can save anyone else, I'd be super happy to hear it. If you have liver disease then don't supplement with mg as it will build and become toxic. This does not mean that mg adversely affects the liver-only if it is diseased. Of course I haven't given you all the info you may require, but I hope this maybe sparks interest. Among other things, discovering my deficiency has saved my marriage.