Interesting, didn't know anything about
that citrate additive or the benefits of its removal.
"Removal of citric acid monohydrate has already taken place in the UK and a "pain free" version has been on the market for some time now. Upon further research it appears the FDA has approved the removal of this ingredient from the US Humira formulation."
And a study on Citrate-free versus regular Humira in regard to injection pain:
/www.ncbi.nlm.nih.gov/pmc/articles/PMC5127965/