I used to take CoQ10 (prescribed by my doc). However, the effect is way too strong for me (or maybe my body simply too sensitive for supplements.)
The good effect is that I have better energy and mental alertness (fell fresher). The bad effect is my chest pain coming back with these energy. At first I follow my doc revision(taking it once every 2 days instead of 1 everyday). It's better but I still got the chest pain (though the intensity has lessen a lot).
Since my body getting better from other thing I consume (esp from chinese licorice), I stop my CoQ10. However, I try to eat foods containing CoQ10 as much as I can even though I stop supplementing CoQ10. So far the food sources works best for me.
I think you may try it if you want, just start slow and low. I started with the lowest CoQ10 tablet I can find in the store.