I read about the remedy oil of oregano and purchased it from an online seller last year. This is really powerful stuff and I've been using it for my son's recurring viral infections with dramatic results. However, the oil actually made my sinus infection much worse. I thought the severity of my symptoms warranted around 8 drops a day under my tongue every 3-4 hours and continued the dose for 4 days. Every day I experienced a worsening of symptoms including asthma and stuffed nose with thick greenish-yellow discharge of mucous. I believe the oregano was responsible for it firstly, because the symptoms eased off when I stopped it and second, I read somewhere that yeast infections are typically exacerbated with good bacteria die-offs which is probably what the oregano was doing in those big doses. I wasn't eating enough yoghurt to compensate either. Just a note to everyone out there to be careful with overdoing the oregano oil. I'm doing far better with 2 cloves of garlic 5-6 times a day, lots of water, the homeopathic remedy arsenicum album 30X every 2-3 hours, and drastic reduction of refined carbs in my diet.