Question: I am a medical doctor and see a lot of people with cancer and a Danish doctor who has been doing a lot of research with Coq10 and cancer found that they needed 400mg daily to get any real benefit. I have had people on CoQ10 for at least 2 years on that dosage and never seen a side effect of any kind. All my adult cancers take this CoQ10 dosage. Are your recommendations not to exceed 50 mg a day too low?
Answer: When people take CoQ10 in high dosages as a daily supplement for many years or decades, we have no idea how this will interfere with their metabolism. It is unnatural to expose the body to such high dosages. What if we learn 20 years from now that people taking more than 200 mg a day actually live a few years shorter or somehow their mitochondria are not functioning as well? As with post-menopausal hormone replacement therapy, it took decades for the scientific community to find out that it caused problems that they had not expected. CoQ10 appears to be a healthy supplement, but who knows for certain that taking more than 100 mg is healthier than taking less? Many people who take CoQ10 also take other supplements, or medications, and we have no idea the interactions that could occur. Plus, what if someone who is used to taking 400 mg a day goes on a trip and forgets their bottle and in the foreign country they can't find CoQ10? If, after years of taking 400 mg their body is used to it, what happens if they stop? What if when they are older and they are on a limited budget they can't afford buying it anymore? There are many answers about high dose CoQ10 use that we don't know yet. We also have reports from quite a few people who actually feel fatigued when they take more than 100 mg daily, maybe from being still too revved up at night while trying to sleep. Perhaps high doses for cancer or other conditions is appropriate, but for the general public taking CoQ10 as a supplement for health promotion, there is no proof that taking very high amounts is beneficial. We also have to consider the cost, CoQ10 is expensive. For the time being I suggest 30 or 50 mg most days of the week for those who wish to take this supplement.