Not on right now- and have only dabbled in AS lightly over the past 18 months or so. Just started cell tech and for 2 days I have had shortness of breath---well, not really shortness of breath but just the urge to take in a deep one every 10 secs or so. Tight feeling in chest. So of course I am thinking I am dying but I am hoping someone has had the same on supplements or maybe I just strained something lifting heavy?