Seriously, I have had S.I joint problems in my lower back for 19 years. When it starts to hurt, I take 800 milligrams of Motrin (Ibuprofin) 3 times a day and it works. The doctor had to prescribe such a high dose so I did not have to take several over the counter. After the first day I have relief and if I keep taking it it continues to relieve me. I usually will stop after I feel better just so I don't get immuned to it. Take it after eating or with milk so that it does not tear your stomach lining up.