CoQ10: ubiquinol or ubiquinone?

What is coenzyme Q10 (CoQ10), and is it good for you?

Coenzyme Q10, also written CoQ10, co Q10 or just Q10, is a fat-soluble compound found in your cells, and your body makes most of what it uses. The British Heart Foundation (BHF) describes it as a vitamin-like substance found in every cell, with especially high levels in the heart and brain. Inside cells it acts as an electron carrier in the mitochondria, the parts that produce energy. Food supplies small amounts, mainly meat, fish and nuts.

Whether a supplement does anything for you is a separate question, and the answer so far is unclear. Claims that CoQ10 helps with energy, heart health, blood pressure, cholesterol or brain function have all been assessed, and every one is listed as non-authorised on the Great Britain register of health claims. In the BHF's words, studies suggest it may have benefits but the results are inconclusive, and there's no agreed effective dose. A 2016 Cochrane review found moderate-quality evidence that CoQ10 has no clinically significant effect on blood pressure.

Much of the research has looked at two groups. In people with heart failure, a 2021 Cochrane review of 11 trials found most were small and all had some risk of bias, and the most favourable results came from a single trial of 420 people. CoQ10 isn't in UK heart failure guidelines, and the BHF says UK doctors don't prescribe it. The other group is people taking statins, covered below.

What is ubiquinol, and is it better than ubiquinone?

Ubiquinol is CoQ10 in its reduced form, and no one has shown that it works better than ubiquinone, the oxidised form, for any health outcome. They're the same molecule in two states. Your cells switch between the two constantly, and CoQ10 travels in the blood mainly as ubiquinol, whichever form you swallowed.

Ubiquinol breaks down easily in air, which is why it only became practical in supplements once manufacturers found ways to protect it. Two small head-to-head studies favour it for blood levels:

• In 2014, 12 healthy volunteers took 200 mg a day of each form for four weeks. Total CoQ10 in the blood rose from 0.9 to 4.3 µg/mL on ubiquinol and from 0.9 to 2.5 µg/mL on ubiquinone. The authors work for a CoQ10 laboratory.
• In 2018, 10 older men took 200 mg a day of each form with a main meal for two weeks. Ubiquinol raised total blood CoQ10 significantly and ubiquinone did not. Six of the 10 men responded more to ubiquinol and two to ubiquinone.

A 2020 review by two employees of a company that makes ubiquinone came to a different view: how well the CoQ10 is dispersed in its oil matters more than which form it's in. It also pointed out that most clinical trials have used ubiquinone. Higher blood levels in a dozen people don't tell you whether either form improves how you feel.

Should you take CoQ10 100 mg or 200 mg?

Neither is the right amount, because the UK has no recommended daily intake for CoQ10 and, as the BHF puts it, there's no agreed effective dose. In trials of statin muscle symptoms, doses ranged from 100 to 600 mg a day. Your gut can only absorb so much at once: a study cited in the 2020 review found that two 100 mg doses raised blood levels more than a single 200 mg dose. So if you take more than 100 mg, splitting it between two meals is reasonable.

On safety, a 2006 risk assessment by scientists at a US supplement trade association found strong evidence of safety at up to 1,200 mg a day. Side effects in trials, mainly stomach upsets, were no more common at high doses than at low ones. No UK body has set an upper limit.

When to take CoQ10: morning or night?

No study has compared morning with night, so the best time is with a meal. CoQ10 is fat-soluble, and the gut absorbs it with the help of bile, so taking it with food that contains some fat makes sense. The US National Center for Complementary and Integrative Health (NCCIH) lists insomnia among CoQ10's mild side effects, so if it seems to keep you awake, take it with breakfast or lunch instead.

CoQ10 and statins: what does the research show?

Statins lower CoQ10 levels in the blood. A 2018 meta-analysis of 12 trials, with 1,776 participants, confirmed this. They do it because the chemical pathway that makes cholesterol also makes CoQ10. That's why people wonder whether a supplement helps with statin muscle aches. The trials disagree:

• A 2020 meta-analysis of seven trials (321 patients) found no benefit for muscle pain compared with placebo, and no effect on whether people stayed on their statin.
• A 2025 meta-analysis of seven trials (389 patients, 100 to 600 mg a day for 30 to 90 days) found a small reduction in pain scores, and its authors said more research was needed before anyone could make recommendations.

The BHF concludes that current evidence doesn't support taking CoQ10 for statin-attributed muscle pain, and the NCCIH says the same. NICE's guideline on cardiovascular disease (NG238) says: "Do not offer coenzyme Q10 or vitamin D to increase adherence to statin treatment."

Muscle aches on a statin often turn out not to be caused by it. A 2022 analysis of 19 double-blind trials involving 123,940 people found that 27.1% of those on a statin and 26.6% of those on a placebo reported muscle pain or weakness. More than 90% of the reports from people on statins weren't due to the drug, and the small excess appeared mainly in the first year.

Can you take CoQ10 with warfarin?

Only if your anticoagulation clinic or GP agrees. Case reports describe people whose warfarin worked less well while they took CoQ10, which is chemically similar to vitamin K. In one report from Denmark, a 72-year-old woman responded less to warfarin until she stopped CoQ10. A small Danish trial in 24 people on stable warfarin found no change in INR (the blood clotting test) with 100 mg a day for four weeks, but a trial that size can't rule out effects in individuals.

The UK product information for warfarin says patients "should generally avoid taking any herbal medicines or food supplements whilst taking warfarin" and should tell their doctor about any they take, because more frequent monitoring is advisable. The BHF adds that CoQ10 may interact with blood pressure medicines, and the NCCIH mentions insulin and some cancer treatments.

Side effects, and who should check first

CoQ10 is usually well tolerated. Reported side effects are mild: stomach upsets, and sometimes difficulty sleeping. Ask your GP or pharmacist before you start it if you:

• take warfarin or another blood thinner
• take insulin or blood pressure medicine, or are having cancer treatment
• are pregnant or breastfeeding, where NHS supplement advice covers folic acid and vitamin D, so ask your midwife or GP before adding anything else

Count every product you take, too. Some multivitamins contain CoQ10, so two products can double your dose without you noticing. Our guides to multivitamins for men and women cover what else to look for on the label, and supplements you can take together covers other common overlaps.

CoQ10 tablets, capsules or softgels: does the format matter?

There's no good evidence that CoQ10 tablets absorb better or worse than capsules, but how the CoQ10 is prepared does matter. A 2020 review of CoQ10 absorption didn't cover tablets at all. It explained that raw CoQ10 is made of crystals the gut can't absorb until they are dissolved or dispersed, and that the best preparations dissolve it in a carrier oil inside a capsule. In one study it describes, a product with dispersed crystals gave about four times the blood levels of the same product without. The review also said the capsule shell itself seems to matter little.

Both of its authors work for a CoQ10 manufacturer, and several of its comparisons rest on single studies, so treat it as a guide to the question, not a verdict. In practice, the format alone tells you little. Look on the label, or ask the maker, how the CoQ10 is dissolved or dispersed.

What's the best CoQ10 supplement in the UK?

No single product is best for everyone, and the form matters less than the label suggests. In the UK, CoQ10 supplements are sold as foods rather than medicines, and the BHF points out that they aren't regulated like medicines and that absorption varies a lot between types. Things worth checking:

• the amount of CoQ10 per capsule, and whether it's ubiquinone or ubiquinol
• an oil-filled softgel or capsule, since CoQ10 dissolves in fat rather than water
• no promises about energy, your heart or blood pressure, because no such claim is authorised in Great Britain
• independent third-party testing, if the brand offers it
• a pharmacist's view if you take any regular medicine

Where Natura fits

Daily Ubiquinol, in the Natura cabinet (coming soon) with our single bottles, is one capsule of 100 mg ubiquinol, and we make no health claim for it. The same capsule is in the Heart Pack (with Daily Omega), the Gums Pack (with Daily Vitamin C, 1,000 mg) and the Joints Pack, listed under body systems and the Fifty. Daily Multi also contains 100 mg of CoQ10 as ubiquinone, so taking it with Daily Ubiquinol, or taking two of those packs, doubles the amount. None of them is for anyone on warfarin unless their anticoagulation clinic agrees.