Ubiquinol vs Ubiquinone: Which Form of CoQ10 Is Better?

Ubiquinone and ubiquinol are the same molecule, coenzyme Q10 (CoQ10), in two chemical states. Ubiquinone is the oxidised form. Ubiquinol is the reduced form. The body converts one into the other all the time, so both are active. Whether ubiquinol absorbs better is disputed: some small trials favour it, a major review calls the idea mistaken, and formulation appears to matter at least as much as the form.

This guide covers the difference between the two forms, what the absorption studies show, why ubiquinol costs more, what the human evidence says about benefits, and how PQQ, a separate compound often mentioned alongside CoQ10, compares.

Key Takeaways

  • CoQ10 is the umbrella name. Ubiquinone (oxidised) and ubiquinol (reduced) are its two forms, and the body switches between them.
  • Head-to-head absorption results conflict. Individual response varies, and the oil carrier and crystal state of the ingredient shape the result.
  • Ubiquinol is less stable and costs more to make. Stability and packaging matter when comparing labels.
  • PQQ is a different compound from CoQ10. The studied adult dose is 20 mg a day, and pregnancy is excluded.
  • CoQ10 can interact with warfarin and blood pressure medicines. A GP or pharmacist should be consulted before use.

Table of Contents

Are ubiquinone and CoQ10 the same thing?

Mostly, yes. CoQ10 is a molecule that occurs in the body in two bioactive states: ubiquinone, the oxidised state, and ubiquinol, the reduced state. Both are important for human health. A label that says “CoQ10” or “coenzyme Q10” without further detail usually means ubiquinone. A label that says “ubiquinol” names the reduced form on the front.

The chemical difference is small. Ubiquinol carries two more hydrogen atoms than ubiquinone. That extra pair makes it an antioxidant, ready to donate electrons. It also makes it unstable: ubiquinol oxidises easily when exposed to air and returns to ubiquinone.

How the body uses both forms

Inside mitochondria, the energy-producing parts of cells, CoQ10 works as a shuttle. Ubiquinone is reduced to ubiquinol by Complex I or II of the respiratory chain. Complex III then re-oxidises ubiquinol back to ubiquinone. A 2024 overview in PMC reports that each CoQ10 molecule goes through roughly 5,000 of these cycles per hour.

CoQ10 shuttle cycle through respiratory chain complexes

This constant switching is the main reason the “active form” label can mislead. Ubiquinone is not inactive. The body already holds both forms in tissues and moves between them. NAD is the other commercially available redox-cycle molecule in that overview, and its research role is outlined in a piece on NAD+ and mitochondrial research roles.

Ubiquinol vs ubiquinone at a glance

Feature Ubiquinone Ubiquinol
Chemical state Oxidised Reduced
Common name on labels CoQ10, coenzyme Q10 Ubiquinol, “active” CoQ10
Stability More stable, easier to package Oxidises readily back to ubiquinone
Typical cost Lower Higher
Preferred format Oil-based softgels or well-dispersed formulations Oil-based softgels with oxygen protection
Heart failure trial evidence Larger body of long-term outcome data Fewer long-term outcome data

Is ubiquinol better absorbed?

The honest answer is that studies point in different directions.

Trials that favoured ubiquinol

A 2014 comparison in 12 healthy volunteers gave 200 mg a day for four weeks. Plasma total CoQ10 rose from 0.9 to 2.5 µg/mL on ubiquinone and from 0.9 to 4.3 µg/mL on ubiquinol, a significantly larger rise for ubiquinol.

A 2018 double-blind crossover trial in 10 older men also used 200 mg a day for two weeks. Ubiquinol raised total CoQ10 1.5-fold, from 1.3 to 3.4 μmol/L, while ubiquinone produced an insignificant rise. Six of the 10 men responded better to ubiquinol.

Evidence that the gap is smaller than claimed

A crossover study in 11 healthy volunteers found no significant difference in plasma CoQ10 after 150 mg of either form. Its authors concluded that intestinal absorption of CoQ10 is highly variable between people and independent of the form given. The 2020 review that reports it goes further and calls the idea of superior ubiquinol bioavailability mistaken, partly because it came from comparing studies that were not head-to-head.

The same review points to a variable that is easy to miss: crystal dispersion. Ubiquinol gave about twice the exposure of ubiquinone that had not been thermally crystal-dispersed, yet only 52% of the exposure of ubiquinone that had. The absence of crystal dispersion cuts bioavailability by around 75%.

Evidence that the gap is smaller than claimed

What this means for choosing

A 2023 review adds that ubiquinol must be oxidised to ubiquinone before it can be absorbed in the gut cells. It also states that bioavailability mainly depends on crystal dispersion status and carrier oil composition. In practice:

  1. The form on the front of the pack is only one factor.
  2. The oil base and the way the ingredient is prepared carry real weight.
  3. Personal response varies, so a single trial result does not predict an individual outcome.
  4. CoQ10 is fat-soluble, so taking it with a meal containing fat is the usual advice.

This is the same principle behind our wider view of absorption, covered in why chemistry matters more than the capsule.

Why ubiquinol costs more

Two reasons recur. Ubiquinol is harder to make and keep, because it reverts to ubiquinone on contact with oxygen. It also needs more protective packaging and formulation, since the 2023 review describes it as very unstable under normal conditions. Those extra steps add cost per capsule.

That instability has a buying implication. A product that has oxidised during storage is no longer delivering what the front label says. Sealed, oil-based softgels and sensible storage are the practical safeguards. Price alone does not show quality in either direction.

Benefits supported by human evidence

Most of the research on CoQ10 comes from heart health, and most of the long-term data come from ubiquinone.

Heart failure research

The British Heart Foundation describes the Q-SYMBIO trial: 420 people with heart failure took 3 × 100 mg of CoQ10 daily for two years alongside usual medicines, and had fewer heart problems and hospital admissions than those on placebo. The BHF adds that benefits remain unclear, more research is needed, and CoQ10 is not part of UK or international heart failure treatment guidelines.

A 2024 meta-analysis of 16 studies found a 40% reduction in heart failure-related mortality (RR 0.60) and better exercise capacity, with no significant difference in left ventricular ejection fraction. Deaths numbered 65 of 1,049 in the treatment groups and 116 of 1,087 in the control groups.

The 2023 comparison of the two forms notes that the cardiovascular death reduction was reported for ubiquinone studies and not for ubiquinol, and that the doses in those ubiquinone studies were much lower. That does not prove ubiquinone is superior. It shows where the long-term evidence sits.

Statin muscle pain

The BHF states that current evidence does not support CoQ10 for muscle pain linked to statins, and that NICE also advises against it for this purpose. Anyone with muscle symptoms on a statin should speak to their GP rather than adding a supplement.

Age and general wellbeing

CoQ10 levels in the body change with age, which is why it features in healthy ageing routines. A supplement is not a treatment for any condition. Nutrition, activity and sleep stay the foundation.

Safety, side effects and medicines

The BHF reports CoQ10 is generally considered safe with few side effects. Some studies report mild stomach effects such as nausea, indigestion and diarrhoea. The same source notes possible interactions with blood pressure medicine and with warfarin.

Practical points:

  • Anyone taking warfarin should speak to their GP, anticoagulant clinic or pharmacist before starting CoQ10. CoQ10 may reduce warfarin’s effect, which can mean more frequent INR checks.
  • Anyone on blood pressure medicines should check first, as effects may add together.
  • Heart conditions call for a conversation with a GP or cardiologist before changing any routine.
  • Pregnancy and breastfeeding: seek advice from a midwife or GP before using any supplement.

Men planning a broader routine can also read this overview of supplements for men over 40 alongside the medical guidance above.

In the UK, food supplements do not need registering. They fall under the Food Supplements (England) Regulations 2003, and the MHRA decides whether a product counts as medicinal. Food supplements may not contain medicinal ingredients or make medicinal claims.

PQQ: how it differs from CoQ10

PQQ (pyrroloquinoline quinone) is a separate compound. It is not a form of CoQ10, so “PQQ vs CoQ10” compares two different supplements, not two versions of one. Both are discussed in connection with mitochondria and energy, which is why they are often found in the same formulas.

What the evidence shows

Human data are limited. A 2012 open-label trial gave 17 adults 20 mg of PQQ daily for eight weeks. Participants showed significant improvements across all six mood measures, plus sleep, appetite and quality of life. With no placebo group, the trial cannot show cause and effect. It is a starting point for research, not proof.

PQQ dosage and safety

The EFSA opinion of November 2017 reviewed twelve clinical studies using doses up to 100 mg for up to 24 weeks and found no safety concerns. It concluded that PQQ disodium salt is safe for healthy adults, excluding pregnant and lactating women, at up to 20 mg a day. That level is at least 250 times the estimated intake from food. This is an EU opinion, and anyone in the UK should follow the label of the specific product.

PQQ should be avoided in pregnancy and breastfeeding because safety data are lacking.

Taking CoQ10 and PQQ together

The two are often combined in energy products. The research above does not test the pairing in head-to-head trials, so no specific combined benefit is established. The same medicine cautions for CoQ10 apply when a product contains both.

A practical way to compare labels

When reading a CoQ10 product page:

  1. Find the form named: ubiquinone, ubiquinol, or just “CoQ10”.
  2. Check the amount per serving in milligrams, not just per bottle.
  3. Look at the carrier: an oil-based fill suits a fat-soluble molecule.
  4. Look for independent batch testing and recognised manufacturing standards.
  5. Check storage guidance, particularly for ubiquinol.
  6. Check allergens, vegan status and whether the dose matches the serving size.

Our view on form, dose and testing

At thecary, preventative health starts with what the body can actually use. A form that looks better on paper means little if the dose, carrier and handling are wrong.

The CoQ10 debate shows this clearly. Studies disagree on which form wins, yet they agree that formulation and individual response drive the outcome. That is why we focus on clinically dosed, bioavailable formulas and on batch-by-batch testing, backed by FSSC 22000 and GMP certification.

Our approach combines ancestral botanicals with modern science. We would rather a customer understand a label than be sold on a buzzword.

Tinashe

Supplements for energy and heart health at thecary

A reader building a preventative routine can browse our energy range and our heart health range. Each product is tested batch by batch, and formulas are vegan and GMO-free.

thecary

The full catalogue, covering sleep, digestion, healthy ageing, immune support and more, is on the thecary collections page. Anyone on medication or with a health condition should check with a GP or pharmacist first.

FAQ

Are ubiquinone and CoQ10 the same thing?

Ubiquinone is the oxidised form of CoQ10, and most standard CoQ10 supplements contain it. CoQ10 as a term also covers ubiquinol, the reduced form. The body converts between the two continuously.

Is ubiquinol better than ubiquinone?

Not clearly. Two small trials found ubiquinol raised blood CoQ10 more, while a crossover study found no significant difference and a 2020 review called the superiority claim mistaken. The oil carrier, crystal dispersion and personal response all affect the result.

Why is ubiquinol so expensive?

It is unstable and reverts to ubiquinone when exposed to oxygen. Making and packaging it so that it stays reduced takes more care, and that raises the cost.

Can CoQ10 be taken with medicines?

CoQ10 may interact with warfarin and with blood pressure medicines, according to the British Heart Foundation. A GP or pharmacist should be asked before starting, especially for anyone who has INR checks.

Sources

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