I have been reading and I see people are bringing up the sinus's to be the cause. I am starting to believe this is true actually. I just recently bought dr. katz sinus plus spray.(yes, I know. Dr. Katz!) anyway, I noticed that my bad breath is gone. Or atleast it appears to be. I then started freaking out that maybe my oldfactory nerves just arent working anymore due to the terrible burning sensation it has caused me. So, i did some research on the ingrediance in the product. It has zinc in it. Come to find out zinc sprays are being linked to oldfactory nerve damage and there are lawsuits even filed because of this. I am getting really worried about this now. NOw I wonder if my bad breath is cured or I just can't detect it anymore. NO one around me backs up when I am talking to them though. I am stumped. Also, I see talk about colliod silver sprays? Maybe that has the same effect on the nerves. I would just be careful. Has anyone else here tried the zinc nasal spray? If so, have you noticed a dulling of your senses?