Target blood levels for Coenzyme Q10 are between 0.5 and 2.5, and supplementation is often recommended by fertility specialists.

“Most physicians will say that they want to see your levels of coenzyme Q10 to be somewhere between 0.5 and 2.5. It's going to depend on the units. Most people, I realize, are not going to run off and get their CoQ10 measured. It's not included in most standard blood tests. But if you were to measure your CoQ10, that's the range that you want to look for. That said, many people opt to supplement with CoQ10. And you'll find that many fertility docs, OB/GYNs, and urologists that are trying to assist their male patients with fertility will suggest CoQ10”