I take flax seed oil 1000mg 3x/day.  My ophthalmologist especially encourages it because I have dry eyes (which I also treat with Restasis).  A few weeks ago, I did a 24-hour urine test and the lab did the wrong one.  They did PGE1 instead of PGD2, and it turns out it was quite low.  I did some research on this, and it is possible that the flax seed oil is using up all of the enzyme (D6D) that is also used to make PGE1, so you get an imbalance.  To make up for this, I just started taking Borage Oil (made from the starflower), which skips the enzyme step and gives you a more direct precursor to PGE1 (GLA, which is an Omega-6 fatty acid).

This is all my hypothesis, but I'm just saying, you might want to make sure you're covering all bases.   Note also that I'm a vegetarian health-food-type, so I may have a lot less of some of these fatty acids in my diet than your average person.

Other things I take specifically to help with pain/inflammation are Turmeric and Green Tea Extract, both of which might upset your system, but I do think they help.