Is 600-1000mg ibuprofen in one dose safe?

i have a muscle knot in my back that wont go away, 2x 200mg advil per dose isnt helping at all, so I upped the dose to 5x 200mg pills and it helped. Is that safe? I'm limiting to having one dose a day because being pain free for a few hours with 1000mg is better than being in pain 24/7 with 400mg every 6 hours