Hydrogen Peroxide is supposed to be diluted with water. Make sure you are doing this. In order to mask the taste I always hold my nose while drinking the HP mixture QUICKLY. Then I have 4 green grapes immediately afterward while I am holding my nose. (You cannot taste anything without the sense of smell). You have to do this quickly though because you cannot hold your breath too long. The green grapes mask the aftertaste. It works! Good luck.