QUERCETIN UPDATE: So I mentioned a while back that I was taking Quercetin and that it seemed to help my sinuses. Quite a few other people (Rand Simberg, for example) reported similar experiences. After several months, I still think it does. I measure this semi-objectively by the drastic reduction in Sudafed consumption that I’ve experienced since taking it. Anyway, you might give it a try if you have sinus issues and don’t want to gobble decongestants. It seems to help.