Mayo Clinic's page on CoQ10 lists dosages that have been used in many different disorders -- a long page of them. The dosage varies a lot. For most disorders, dosages seem to range between about 20mg and 600mg. For neurological and mitochondrial disease, the dosages used are much higher. For example,
To treat mitochondrial diseases, 120-1,200 milligrams of CoQ10 has been taken by mouth daily for up to one year. A liquid form of CoQ10 has been taken by mouth at a dose of 5 milligrams per kilogram daily. A dose of 2 milligrams per kilogram of CoQ10 has been taken by mouth daily for six months.
To treat Parkinson's disease, nanoparticular and standard CoQ10 formulas have been taken by mouth in doses of 300-2,400 milligrams daily for four weeks to 16 months.
To treat amyotrophic lateral sclerosis (ALS), 1,800 or 2,700 milligrams of CoQ10 has been taken by mouth daily in three divided doses for nine months. Doses of CoQ10 as high as 3,000 milligrams have been taken by mouth daily for eight months.
I took 200 mg CoQ10 for several years with no noticeable effect. A few months ago I increased to 1200 mg (600 mg morning, 600 mg at lunch) and have noticed that I have some more energy and I'm not as tired by evening as I used to be. I'm not planning to stay at this dose permanently. My guess is that I was severely depleted. Hopefully I'm now back into a healthier range and may be able to maintain with a dosage in the 200 - 600 mg daily range. I'll just have to experiment, I suppose.
I have had no bad side effects from it at all, but I'm not generally hypersensitive to meds and supplements. I am careful to take it early in the day because I've read it can cause insomnia if taken after midday.
ggingues' suggestion to get your CoQ10 level tested, if you can, is a good one. That would probably be the best way to figure out the appropriate dose for you.
