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CoQ10 and Ubiquinol Supplements Reviewed by


Studies with CoQ10 have not shown serious adverse effects at moderate doses even when taken for several years — although it may be best to divide the dose over the course of the day. (For more information about CoQ10 dosages used for reducing statin-related muscle pain, congestive heart failure, migraines and other uses, see the Dosage section of the Review).

Also, be aware that CoQ10 and ubiquinol may affect your response to certain medications. For more details, see the Concerns and Cautions section of the CoQ10 and Ubiquinol Supplements Review.

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January 15, 2020

I am 68 and must deal with low-tension glaucoma in one eye that has a defective nerve. So I try everything that research suggests, including coQ10.
As you must all know, absorption is a problem, so one must use the 'enhanced' formulas such as mitoQ and others. I started about two years ago.

About the time I started (mitoQ), I had an echo-cardiogram that showed slight defects in two valves. About a year later, I had a more extensive echo-cardiogram, and nothing was detected! Some substance or combination had fixed that! Also modest periodontal problems disappeared. My eye, on the other hand, remained a problem.

It may be combinations that get effects. I also took at the time nicotinamide riboside, pterostylbene, and citicoline. But heart effects are attributed to coQ10. So it's useful to consider that.

January 15, 2020

I have been taking 100mg CoQ10 for many years to counteract its loss in the body when taking statins which I have also been taking for a long time. I take atorvastatin 10mg and wonder how to determine how much CoQ10 I actually need. I have arbitrarily taken 200mg at various times. I don't notice any physical effects so it is hard for me to tell how to assess the correct dosage. I am 85, in good health and with a good blood panel (low risk for heart disease).
January 16, 2020

Hi Niela - Please use the "Dosage" link in the answer above for details about CoQ10 dosage for helping to reduce statin-related side effects and other uses.

April 4, 2018

I have been taking Vitacost 200 mg Q10-ubiquinone for years. I am in my early 60's, and have a bad case of dry eye. I also have worn contact lenses for 50 years. I don't know if there is an association between the Q10 and my dry eye, or it's age. I will stop taking the Q10 for a few weeks, and see if that helps with my dry eye. So glad I saw all of your comments, so I can see if these work or not.

January 15, 2020

Some types of omega 3 fatty acids supposedly deal with dry eye, but research shows no effects. Nevertheless, it works for some.

For visual blurriness, please try citicoline. I get consistent and rather impressive results. Citicoline acts on the optical nerve, and it's unclear how this works, but I have heard others also.
January 16, 2020

Hi Helen - Thank you for sharing this. There is some preliminary evidence that citicholine may help to slow the progression of a certain type of glaucoma (, although we are not aware of studies on the effects citicholine on blurry vision in general. You can find information about omega-3s and dry eye in the Fish Oil Review (

April 4, 2018

Have been taking Bluebonnet Ubiquinol for years with no side effects and no vision impairment, in fact I rarely need glasses.

Gave my dog who was diagnosed with a heart condition 100mg of Ubiquinol and when she was last checked her heart was completely normal.

January 24, 2019

was this a large dog? thanks

June 30, 2019

my dog has an irregular heart beat. He is a 65 pound hunting dog-wirehaired pointing griffon
how much does your dog weigh and how much do you give her.
What was her heart condition?

Philip 16656
April 3, 2018

I cut back from 200mg to 100mg of Ubiquinol and my visual sensitivity has improved.

Philip 16655
April 3, 2018

Can CoQ10 have an adverse effect on my vision ?
April 3, 2018

Hi Philip - Although we aren't aware of any clinical studies or published case reports suggesting that CoQ10 has an adverse effect on vision, two other CL members have reported a similar issue in the comments section of the CL Answer about CoQ10 side effects:

December 26, 2018

I don't know about others (or any studies), but I can say for sure that taking CoQ10 has caused "blurry" vision for me. I tested over and over by stopping and starting. For some reason CoQ10 affects my vision. It's the weirdest thing.

December 30, 2018

How long did it take for your vision to clear after stopping the CoQ10? My wife has blurred vision and has been stopped for one week with no improvement.

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