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Ubiquinol vs. Ubiquinone: What CoQ10 Studies Actually Compare

The Dose Analysis

Ubiquinol vs. ubiquinone is a comparison of two forms of the same molecule, coenzyme Q10 (CoQ10). Ubiquinone is the oxidized form and ubiquinol is the reduced form. Small studies that compared them measured how much CoQ10 appeared in the blood afterward, and their results were mixed. They did not measure how people felt or any health outcome, and the one study that measured energy (ATP) in blood cells found no change with either form. So they show which form raised blood CoQ10 more in those groups, not which form works better for a person.

Key takeaways

  • Ubiquinone (oxidized) and ubiquinol (reduced) are two forms of CoQ10. In a 2020 study, CoQ10 appeared in the blood mostly as ubiquinol even when people took ubiquinone.
  • Two small studies at 200 mg a day found a larger rise in blood CoQ10 with ubiquinol; a 2020 single-dose study found a difference that was not statistically significant.
  • These studies measured blood levels, not health outcomes. NCCIH says CoQ10 may interact with warfarin and insulin.

Two forms of one molecule

CoQ10 is a substance naturally present in the human body, with the highest levels in the heart, liver, kidneys and pancreas, according to the National Center for Complementary and Integrative Health (NCCIH).

A 2018 paper by Zhang and colleagues in Food & Function explains that CoQ10 works through its ability to accept and donate electrons. Ubiquinone is the oxidized form, ubiquinol is the reduced form, and the paper notes that ubiquinone, the form commonly used in supplements, must be reduced to ubiquinol to carry out CoQ10's functions after it is consumed. A 2020 study by Pravst and colleagues in Nutrients found that CoQ10 appeared in the blood mostly as ubiquinol, even when participants swallowed ubiquinone.

Absorption is the other half of the question. A 2006 review by Bhagavan and colleagues in Free Radical Research describes absorption of dietary CoQ10 as slow and limited, because it is a large molecule that does not mix with water, and reports that solubilized formulations show better absorption.

What the comparison studies measured

Study Who and how much What it found
Langsjoen, 2014 12 healthy volunteers; 200 mg a day of each form for 4 weeks, softgels with identical other ingredients Plasma CoQ10 rose more with ubiquinol than with ubiquinone
Zhang, 2018 10 older men; 200 mg a day of each form for 2 weeks Ubiquinol raised plasma CoQ10 significantly; the rise with ubiquinone was not significant; no change in oxidative stress markers
Pravst, 2020 21 healthy adults aged 65 to 74; one 100 mg dose of each form Ubiquinol was 1.7-fold higher than ubiquinone, a difference that was not statistically significant

Langsjoen, 2014: 12 healthy volunteers

In this study in Clinical Pharmacology in Drug Development, 12 healthy volunteers took 200 mg a day of ubiquinone for 4 weeks, stopped for 4 weeks, then took 200 mg a day of ubiquinol for 4 weeks. Both softgels had identical other ingredients, so the form was the main difference. Plasma total CoQ10 rose from 0.9 to 2.5 µg/mL with ubiquinone and from 0.9 to 4.3 µg/mL with ubiquinol, and the authors describe this as superior bioavailability for ubiquinol. No side effects were noted.

Zhang, 2018: 10 older men

This double-blind crossover trial gave 10 older men 200 mg a day of each form for 2 weeks, with a 2-week break between. Ubiquinol significantly raised plasma total CoQ10, while the increase with ubiquinone was not significant. Six of the 10 men responded more to ubiquinol and 2 responded more to ubiquinone. Neither form changed CoQ10 levels inside blood immune cells, energy (ATP) in those cells, or the measured markers of oxidative stress. The authors concluded that ubiquinol appeared to be a better supplemental form to raise CoQ10 status in older men; with 10 participants and 2 weeks per form, it is a very small study.

Pravst, 2020: 21 adults aged 65 to 74

This randomized crossover study gave 21 healthy adults aged 65 to 74 a single 100 mg dose of three products a week apart: ubiquinone capsules, ubiquinol capsules and a water-soluble CoQ10 syrup. Over 48 hours, blood CoQ10 from ubiquinol was 1.7-fold that from ubiquinone, a difference that was not statistically significant, while the water-soluble syrup was 2.4-fold higher. PubMed lists funding from the Slovenian Research Agency and Valens Int.; the authors declare no conflicts of interest.

Why blood levels are not the same as results

A higher blood level is a marker of absorption. It does not show, by itself, any change in energy or health, and none of the three studies above measured a health outcome. The one study that looked inside cells, Zhang 2018, found no change in cell CoQ10 or cell energy (ATP) with either form, and no change in the oxidative stress markers it measured in plasma.

Outcome research on CoQ10 in general is limited. NCCIH says the few studies on preventing heart disease are inconclusive, research in heart failure is also inconclusive, and a 2017 evaluation concluded that CoQ10 is not helpful for Parkinson's symptoms. Those findings come from research on those conditions and do not compare the two forms.

How to read the form on a CoQ10 label

The research above suggests that the form, the amount and the formulation can all change how much CoQ10 reaches the blood. When you read a label, check three things:

  • Form: whether the label says ubiquinone or ubiquinol. A label that says only "CoQ10" does not tell you which one.
  • Amount per day: the milligrams per serving times the servings the directions call for. The two multi-week studies above used 200 mg a day.
  • Formulation: softgel, capsule or liquid. The studies tested specific products, and the result for one formulation does not automatically apply to another.

How the CoQ10+ label compares

CoQ10+ lists 200 mg of Coenzyme Q-10 (Ubiquinone) per 1-capsule serving, with rice flour and a hypromellose (vegetable) capsule as the other ingredients. The suggested use is one capsule once a day; for best results, take it 20-30 minutes before a meal with an 8 fl oz glass of water, or as directed by your healthcare professional. It is ubiquinone, the form used as the comparison in the studies above, and its 200 mg matches the daily amount in the Langsjoen and Zhang studies and is twice the single 100 mg dose in the Pravst study. None of these studies tested CoQ10+, and they used other formulations, so their blood-level results cannot be assumed to apply to it. The label warning reads: "Do not exceed recommended dose. Pregnant or nursing mothers, children under the age of 18, and individuals with a known medical condition should consult a physician before using this or any dietary supplement. Keep out of reach of children. Do not use if safety seal is damaged or missing. Store in a cool, dry place."

If another formula you take also lists CoQ10, add the amounts together and do not double up.

Safety: what to know before you try it

NCCIH says no serious side effects of CoQ10 have been reported, and that mild side effects such as insomnia or digestive upsets may occur.

CoQ10 may interact with the blood thinner warfarin and the diabetes drug insulin, and it may not be compatible with some types of cancer treatment, according to NCCIH. If you take any medicine, talk with your health care provider first.

If you take a statin, talk with your prescriber before adding CoQ10. NCCIH says that although individual studies have varied, the overall evidence does not support the idea that CoQ10 reduces muscle pain caused by statins.

If you are pregnant, nursing or trying to conceive, ask your healthcare provider before use.

Frequently asked questions about ubiquinol vs. ubiquinone

Is ubiquinol better than ubiquinone?

The evidence is limited to blood levels. Two small studies at 200 mg a day, Langsjoen 2014 and Zhang 2018, found a larger rise in blood CoQ10 with ubiquinol, while the 2020 Pravst single-dose study found a difference that was not statistically significant. None of them measured a health outcome, and the one that measured energy (ATP) in blood cells, Zhang 2018, found no change with either form.

Does the body convert ubiquinone to ubiquinol?

Yes. Zhang and colleagues note that ubiquinone must be reduced to ubiquinol to carry out CoQ10's functions, and the 2020 Pravst study found CoQ10 in the blood mostly as ubiquinol even when people took ubiquinone.

What should I look for on a CoQ10 label?

Look for the form (ubiquinone or ubiquinol), the milligrams per serving, the number of servings a day and the type of product, such as a softgel, capsule or liquid. The studies above tested specific formulations, so compare the label with what was actually studied.

Can I take CoQ10 with a blood thinner?

Talk with your health care provider first. NCCIH says CoQ10 may interact with the blood thinner warfarin, as well as with insulin.

Does CoQ10 help with muscle pain from statins?

NCCIH says the overall evidence does not support the idea that CoQ10 reduces muscle pain caused by statins, even though individual studies have varied. If you have muscle symptoms while taking a statin, talk with your prescriber.

Related reading

Sources

The Dose Analysis and CuraMyHealth are both operated by Hofer LLC. Purchases linked from our reviews take place on CuraMyHealth.

This article is for education and is not personal medical advice. A qualified healthcare professional can help assess your needs and review the specific formula. Individual results vary.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

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