Imagine having to inject yourself with citric acid once a week and wait for the burning sensation in your leg to dissipate which could take days. For those on Humira in Canada this is the reality. Here is my story.at 24 I was diagnosed with Crohn's disease tried multiple medications. almost 3 to 4 years later I started humira. every time I inject i have a burning sensation shoot down my leg lasting for up to 24 hours. I have the option of injecting in the stomach but don't because the thought of a burning sensation going through my stomach is offputting. we need to bring the citrate free formula to Canada.