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ubiquinol vs. ubiquinone

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Ubiquinol vs. ubiquinone: which version of CoQ10 is superior?


If you’ve tried or researched CoQ10 for fertility, you may be wondering: What’s the difference between ubiquinol and ubiquinone CoQ10? Is one better than the other? Why is ubiquinol more expensive — and is it worth it? Read on to understand ubiquinol vs. ubiquinone found in health supplements and what the research says about using CoQ10 for fertility.

The difference between ubiquinol and ubiquinone

Both ubiquinol and ubiquinone are forms of CoQ10 (coenzyme Q10), an antioxidant often used to support fertility, heart health, and overall wellness. Antioxidants are crucial for protecting the body’s cells against free radicals and oxidative stress, which can lead to chronic diseases and be detrimental to the health of your sperm.

From a chemistry standpoint, the primary difference between ubiquinol and ubiquinone is that ubiquinol is the reduced form of CoQ10, whereas ubiquinone is the oxidized form. That means that ubiquinone has more electrons than ubiquinol. But does that small — like, microscopic — difference actually change the way they work?

CoQ10 is produced naturally in the body, and helps to generate energy in all cells; the highest levels of CoQ10 are found in organs with high rates of metabolism such as the heart, kidney, spleen, and liver. In the body, CoQ10 molecules actually convert back and forth from the oxidized form to the reduced form and back again over and over. Both ubiquinol and ubiquinone supplements are safe, and research shows they function similarly in the body.

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Is ubiquinol better than ubiquinone?

Some researchers have hypothesized that ubiquinol is more “bioavailable.” Bioavailability is a term that refers to the ability of a drug or other substance to be absorbed and used by the body. In one 2018 study of older men, two-week supplementation with ubiquinol resulted in enhanced CoQ10 activity when compared to ubiquinone supplementation. However, the research is mixed.

A 2020 study found that there is no statistically significant difference in bioavailability between ubiquinol and ubiquinone. Even when consumed as ubiquinone, CoQ10 appeared in the blood almost exclusively as ubiquinol, indicating that the body is capable of converting the coenzyme into its most effective form.

And another study from 2019 suggested that the type of supplement actually matters more than the form of CoQ10 for bioavailability. After testing seven different supplements, researchers found that soft-gel capsules containing either ubiquinone or ubiquinol were most effective.

Taking these studies into account, there is no strong evidence to suggest ubiquinol is superior when taken in supplement form.

There is no statistically significant difference in bioavailability between ubiquinol and ubiquinone. Even when consumed as ubiquinone, CoQ10 appears in the blood almost exclusively as ubiquinol, indicating that the body is capable of converting the antioxidant into its most effective form.

Benefits of ubiquinone CoQ10

One notable thing about ubiquinone CoQ10 is its history. There have been thousands of clinical trials conducted with ubiquinone CoQ10, including fertility studies and studies on heart health — and very few with ubiquinol. (This is not to imply that ubiquinol would be less effective. Research shows that when comparing ubiquinol vs. ubiquinone, they function similarly and are comparatively bioavailable.)

Ubiquinone appears to be more stable when compared to ubiquinol, and is less expensive to manufacture.

The benefits of taking ubiquinone CoQ10 include:

Using ubiquinone CoQ10 for fertility

As mentioned above, CoQ10 is an antioxidant, a compound that protects the human body’s cells against free radicals and oxidative stress.

Free radicals are unstable molecules produced as natural byproducts of daily life, such as toxin exposure, illness, and poor lifestyle. If left unchecked, free radicals can cause damage to our cells. This damage is known as “oxidative stress,” and can be detrimental to the health of your sperm.

Oxidative stress has been linked to male infertility, and is found in 30–80% of infertility cases. A man’s sperm quality often decreases as he ages; CoQ10 levels also decline with age, making high-energy functions like sperm development less efficient and more difficult. (CoQ10 levels also dip in women, affecting female fertility as well.)

Get tips to optimize sperm health so you can achieve your parenthood dreams.

As early as 1997, researchers have studied the correlation between CoQ10 and sperm health. Research has indicated that ubquinone CoQ10 supplementation can enhance fertility, possibly improving sperm concentration, motility (ability to swim), and morphology (size and shape of sperm) when taken as part of a healthy lifestyle. This research includes:

  • A 2009 study, in which patients with reduced sperm motility were treated with 200mg of CoQ10 per day for six months. Patients experienced increased antioxidant levels in semen and improved sperm motility during the course of the study.
  • A 2013 study, in which men with low sperm count and poor motility/morphology also received 200mg of CoQ10 daily, but for three months. Compared to the placebo group, the supplement group was associated with significant improvement in sperm morphology.
  • A 2020 study that pooled data from three clinical trials on CoQ10, in which researchers found that supplementation had a profound effect on sperm motility over a course of 3-6 months.

Because many energy-dependent processes in sperm cells rely on the availability of CoQ10, many male fertility supplements contain ubiquinol or ubiquinone.

Supplements works best in conjunction with healthy lifestyle factors including a nutritious diet, moderate exercise, and adequate sleep, which are all important for fertility and overall health. It is also recommended that people who are actively trying to improve their fertility quit smoking, limit their sugar intake, and reduce their alcohol consumption. Visit our Guide to Sperm Improvement for more tips.


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