How many mg of Ibuprofen can you take at one time? I have a toothache...my root canal is sch for later today but i have to be at work in the meantime, I took one 600mg tablet this am and it still hurts real bad, like when I talk and when I drink. how many can i take in one dose?; I went and had my root canal yesterday, thank you all for your advise, everything went well and i have new pain medication and an antibiotic. *thumbs up*