My local herbalist told me I must never take tea tree oil or any essential oils orally. I use tea tree oil out of the bottle for minor skin irritations/external use but always dilute it first. I had also been using it on my cat for a skin condition but then my vet mentioned tea tree oil and all essential oils are toxic to cats (its something to do with their livers being unable to process the oils I think he said and that it had an accumlative effect). Maybe you can get away with taking it orally for a short while but perhaps the toxic effects buiild up...I dont know but personally I think it best to avoid taking it orally if in any doubt.