You know, T-Bone, I've been thinking about your question for a few days. I'm not sure I have a good answer for you!
We all know COQ10 is a good ingredient to add to anything health related. But then again, i could come up with a big list of other ingredients that aren't in OT. Simply put, I believe the formula is complete as it is. Since we cover alot of bases with it (Joint, Digestion, Multi and immune), I think it's a case of "Should/can you fit more?"