I've been taking this stuff for 3 weeks now, anywhere from 2 - 4 50mg doses a day. Immediately I noticed when running my gas powered weed eater before mowing that my chest pains from Angina were nearly gone. I used to get severe chest pains while weed eating about half way though my lawn and always had to stop until my heart slowed down. Zinc allows red blood cells to carry more oxygen and that is some of the problem with Angina - pain because of restricted blood or oxygen flow to the heart. For me Angina attacks are caused by anxiety from physical or emotional stress and chest pains radiate down my arm into my joints and up to my teeth and jaw. It's quite scary because I was awakened at night with chest pains if I dreamed about running or stressful activity!! I also added Benfotiamine, R-ALA, L-Carnitine, & L-Arginine. This combination seems to help and allows me to exercise a little more without fear of the pain. I see why body builders use it as it supplies more oxygen to the muscles during a workout. I actually discovered the benefits of Zinc Gluconate while reading a double blind study about immune system benefits. One person in the study group asked if he was receiving the placebo or the Zinc. He needed to know because his Angina went away and he was able to ski again. The researchers revealed that he was getting the Zinc Gluconate. You didn't have to tell me twice to try it...and now I'm sold! :D Cheers Cheer