I took 35% H2O2 (Hydrogen-Peroxid) for about a month but had to quit as I slowly at first but getting worse every day started to cough up flem and became very short of breath. I tried to stick it out but when I got to 14 drops 3 times a day I was coughing constantly and even in the night quit a few times. Since I quit, over 3 weeks ago, my cough has subsided to just a few times a day. I might start taking it again in the New Year