Ubiquinol is not an alternative to CoQ10. It is one of the two forms of CoQ10. The other form, ubiquinone, is what most CoQ10 supplements contain, and your body converts between the two all the time. The real differences are practical: ubiquinol may raise blood levels more in some people, while ubiquinone is more stable, has been used in most of the research and usually costs less. This guide compares the two side by side so you can decide which suits you, and explains why our CoQ10 300mg capsules use ubiquinone.
The quick answer
- Same compound, two forms. Ubiquinone is the oxidised form, ubiquinol the reduced form. Your body switches between them.
- Choose ubiquinone if you want the most-researched, more stable and usually cheaper form, or a vegan capsule.
- Consider ubiquinol if you are happy to pay more for a form that, in a small study, raised blood CoQ10 levels more.
- Either way, take it with a meal that contains some fat, and speak to your pharmacist if you take warfarin or diabetes medicines.
What is ubiquinone?
Ubiquinone is the oxidised form of coenzyme Q10 (CoQ10), a compound your body makes and uses in normal cellular energy production. When a label just says "CoQ10" or "coenzyme Q10", it almost always means ubiquinone. It is the form that has been sold for longest, and most of the clinical research on CoQ10 has used it.
Ubiquinone is a stable powder, which means it can be put into ordinary capsules. Ours are vegan HPMC capsules with ubiquinone and nothing else added to the capsule shell.
What is ubiquinol?
Ubiquinol is the reduced form of CoQ10. "Reduced" is a chemistry term: ubiquinol carries two extra electrons and hydrogen atoms. Your body continually converts ubiquinone to ubiquinol and back again as part of how CoQ10 works in cells, and most of the CoQ10 circulating in your blood is in the ubiquinol form.
That has led to marketing that calls ubiquinol the "active" form. The more accurate description is that both forms are active, because the body moves between them. Ubiquinol supplements simply supply the reduced form directly.
CoQ10 (ubiquinone) vs ubiquinol: comparison table
On a phone, scroll the table sideways to see every column.
| Feature | Ubiquinone (standard CoQ10) | Ubiquinol | What it means for you |
|---|---|---|---|
| Chemical form | Oxidised | Reduced | The body converts between them, so both supply CoQ10. |
| Research history | Used in most CoQ10 trials | Fewer trials, available as a supplement more recently | If you are following a study, check which form it used. |
| Blood levels | Raises blood CoQ10 | Raised blood CoQ10 more in a small study of healthy adults | Higher blood levels have not been shown to mean better results. |
| Stability | Stable as a powder | Oxidises in air, so needs protecting | Ubiquinol is usually sold in oil-filled softgels. |
| Typical format | Capsules, tablets, softgels | Mostly softgels, which may contain gelatin | Vegans should check the capsule shell. |
| Cost per mg | Usually lower | Usually higher | Compare price per mg of CoQ10, not price per pack. |
| Side effects | Usually mild and digestive | Usually mild and digestive | No meaningful difference. |
| Interactions | Same for both: may interact with warfarin and insulin, and may not suit some cancer treatments. | Speak to your pharmacist before starting either. | |
Absorption: is ubiquinol better absorbed?
This is the main argument for ubiquinol. In a small comparison study in healthy adults, Langsjoen and Langsjoen found that ubiquinol raised blood CoQ10 levels more than the same amount of ubiquinone (Langsjoen and Langsjoen, 2014).
There are three things to keep in mind:
- It was a small study. Results from a handful of people do not tell us how everyone responds.
- Formulation matters. How well any CoQ10 is absorbed depends a lot on the product, for example the oil it is mixed with, and on whether you take it with food.
- Blood levels are not outcomes. A higher number on a blood test has not been shown to translate into a better result for any particular use.
Both forms are fat-soluble, so taking either with a meal that contains some fat makes a real difference to absorption.
Stability, capsules and cost
Ubiquinol reacts with oxygen and turns back into ubiquinone when it is exposed to air. To stop that happening on the shelf, manufacturers usually dissolve it in oil and seal it in a softgel. Softgels are often made with gelatin, so they may not suit vegetarians or vegans, and the extra processing is one reason ubiquinol tends to cost more.
Ubiquinone is stable as a dry powder, so it can go into simple plant-based capsules. That is why our CoQ10 300mg capsules use ubiquinone in a vegan HPMC shell.
Which should you choose? A decision table
| If you... | Consider | Why |
|---|---|---|
| Want the most-researched form | Ubiquinone | Most CoQ10 trials have used it. |
| Are vegan or vegetarian | Ubiquinone in a plant capsule | Ubiquinol softgels often contain gelatin. |
| Want the lowest cost per mg | Ubiquinone | Simpler to make and store. |
| Want the form that raised blood levels more in one study | Ubiquinol | Evidence is limited, and it usually costs more. |
| Take warfarin, insulin or cancer treatment | Speak to your GP or pharmacist first | The interactions apply to both forms. |
How to take either form
- With food: take it with a meal that contains some fat.
- Split larger amounts: if your serving is more than one capsule, taking them at different meals can help absorption and reduce stomach upset.
- Earlier in the day: a few people find CoQ10 affects their sleep, so breakfast or lunch is a safe default.
- Follow the label: our serving is 2 capsules a day (600mg of ubiquinone). A 2006 safety review set an observed safe level of 1,200mg a day (Hathcock and Shao).
For possible side effects and interactions, see our CoQ10 side effects guide. If you take a statin, read our guide to CoQ10 and statins.
Who should speak to a GP or pharmacist first
- anyone taking warfarin or another blood thinner
- people with diabetes, especially if taking insulin
- anyone having chemotherapy or radiotherapy
- people taking statins or blood pressure medicines
- anyone pregnant, trying to conceive or breastfeeding
- anyone with liver or kidney disease or a heart condition
The bottom line: CoQ10 or ubiquinol?
Ubiquinone and ubiquinol are two forms of the same compound, and your body switches between them. Ubiquinol may raise blood levels more, based on limited evidence, but costs more and usually comes in softgels. Ubiquinone is stable, the form used in most research, suits a vegan capsule and is usually better value. For most people, taking either form consistently, with food, matters more than which one you pick. To find out what the research says about CoQ10 overall, read our guide to what CoQ10 is good for.
Vanessa holds a Level 3 Diploma in Nutrition and co-founded NutritionGo, where she leads editorial content. She researches and writes our guides, covering ingredient composition, traditional use and nutrition information, and fact-checks them against UK advertising rules and the GB Nutrition and Health Claims register. Every factual statement is verified against sources such as the NHS, the GB Nutrition and Health Claims register or peer-reviewed research on PubMed before publication. Vanessa is not a registered dietitian or healthcare professional, so this guide is for general information and is not a substitute for personal medical advice.
References
View all 4 references and sources
- Langsjoen PH, Langsjoen AM. Comparison study of plasma coenzyme Q10 levels in healthy subjects supplemented with ubiquinol versus ubiquinone. Clin Pharmacol Drug Dev, 2014;3(1):13-7.
- Hathcock JN, Shao A. Risk assessment for coenzyme Q10 (ubiquinone). Regul Toxicol Pharmacol, 2006;45(3):282-8.
- National Center for Complementary and Integrative Health. Coenzyme Q10. Safety and interactions.
- Garrido-Maraver J et al. Clinical applications of coenzyme Q10. Front Biosci (Landmark Ed), 2014;19:619-33. Background on the ubiquinone and ubiquinol forms.