depending on how highly concentrated it is, you might need to dilute it with olive oil or something before applying it to the skin. i've never used it topically actually, only ingested it. it burns a decent amount when you swallow it, but it goes away after 20 seconds. it clears up your sinuses really quick, it helps with indigestion, and if taken at the early onset of a cold it can really help fight it off quicker.
i was sick for the past week...didn't take oregano oil in the beginning because it hit me pretty quickly overnight. i was sick for a good 3 solid days. my bf started to feel like he was getting sick, took oregano oil regularly for a couple of days and it never hit him like it hit me.