There is a natural enzyme called CoQ-10 that is present in all our cells that is available as a supplement over the counter. It's relatively expensive tho I see drug stores put it on sale as a 'buy 1, get another free" for about $50 for the 2 containers. Most insurance will not pay for it even if it is prescribed by a physician .
It is said to help offset side effects of statins and aids in glucose control. The only time I've seen it not recommended is if one is on coumadin or other blood thinners.
I've been taking it for about 5 years.
You can do your own research to determine if it is any good or not but I've never seen any study saying it didn't help or has any negative effect other than the blood thinner thing.