I have never written a bad review & i usually love the NOW brand for vitamins & other things. but my first time using the NOW Food Mental Focus blend 5 drops in a diffuser for maybe 2-3 minutes (diffuser did 30 min on & 30 min off rotation) & i started having a severe allergic reaction. As far as i know, i am not allergic to anything, but this EO mixture inhaled via diffuser caused me to start to feel dizzy, then weak, then started to cause my throat to feel like it was swelling up. all within mSee full review