Supplements
How much CoQ10 should you take? The doses used in research, and what to check first
Reviewed by a qualified clinician · analysed at UKAS-accredited UK labs (ISO 15189)
Last reviewed September 20265 min read
Every Helvy guide is written by our health editors, then checked by a qualified clinician before it goes live and re-checked as the science moves. We name clinical roles, not individuals, until each reviewer has agreed to be credited publicly. This is wellness guidance to help you understand your own data, not a diagnosis.
QUICK ANSWER
There is no official UK amount for CoQ10. Research trials have used 30 mg to 400 mg a day, and the British Heart Foundation says no effective dose has been agreed. Take it with food, because your gut needs fat to absorb it. If tiredness is the reason you are buying, test the common causes first.
Find the test that checks the usual causes →As of September 2026. The newest dose figures come from a October 2024 review in BMC Cardiovascular Disorders, which pooled 32 trials and 3,763 people.
You pick up a tub and the numbers make no sense. One says 30 mg. The one beside it says 300 mg and costs four times as much. Nothing on either label tells you which is right for you, because nobody has settled that question.
1. How much CoQ10 do the trials actually use?
Anywhere from 30 mg to 400 mg a day. That is the honest range.
CoQ10, short for coenzyme Q10, is a substance your body makes itself. Your cells use it to turn food into usable energy. It has no Nutrient Reference Value, which is the official daily figure printed on most vitamin labels. No such figure has ever been set for CoQ10, so a label cannot tell you what a full dose looks like.
“There is no agreed effective dose for CoQ10, and its absorption can vary a lot according to the type of supplement taken.”
Dell Stanford, Senior Dietitian, British Heart Foundation, 2025
The very high numbers you see quoted online have a specific source. They come from trials in people with heart disease, run alongside prescribed medicines. One long trial gave 100 mg three times a day for two years. The BHF is clear about what that means for everyone else: CoQ10 “is not recommended in UK and international heart failure treatment guidelines and it is not prescribed by UK doctors”.
So there is no dose to copy. There is only a range that researchers have tried, and most of them were studying people who were unwell.
2. Is a bigger dose better?
For tiredness, the pooled data leans that way. It is a weak lean.
A 2022 review in Frontiers in Pharmacology pooled 13 randomised trials and 1,126 people. It found that “increases in the daily dose and treatment duration of CoQ10 supplementation were correlated with greater fatigue reduction”.
Read that carefully. It is a pattern across trials, not a head-to-head test of two doses in the same people. Most of the benefit in that review showed up in people who had an illness. In healthy volunteers the result did not reach significance. Our guide on whether CoQ10 helps with tiredness takes that apart properly.
There is also a cheaper question worth asking before you go up a dose. Is CoQ10 the right thing at all? Tiredness far more often traces to your thyroid, vitamin B12, vitamin D or your stress hormone cortisol. Those are all measurable. A supplement is a guess until you have checked them.
3. Does the form change the dose you need?
This is the reason ubiquinol costs more, and the evidence is thin.
CoQ10 sits in your body in two forms. Ubiquinone is the standard form in most capsules. Ubiquinol is the form your body converts it into. The pitch for ubiquinol is that you absorb more of it, so a smaller number on the label goes further.
A 2026 crossover trial in 12 healthy adults is the study behind this year's wave of ubiquinol articles. It found one ubiquinol capsule absorbed about twice as well as a ubiquinone one. A ubiquinol maker co-ran it, and it measured blood levels rather than how anyone felt. Our CoQ10 guide covers the counter-evidence.
So you cannot convert one form into the other on the label. Nobody has published a dose chart that does it, and no trial has shown that either form eases tiredness better.
4. How should you take it, and who should not?
Four practical points, and one real interaction to know about.
- Take it with a meal. CoQ10 dissolves in fat, so your gut absorbs it alongside the fats in food.
- Try the morning first. The US National Institutes of Health lists trouble sleeping among its mild side effects.
- Warfarin is the known interaction. CoQ10 may affect this blood thinner. Speak to your doctor before starting.
- Give it months, not days. No trial in that 2022 review showed a quick change.
If you are taking CoQ10 because a statin gives you aching muscles, the BHF verdict is direct. Current evidence “does not support taking CoQ10 supplements for statin-attributed muscle pain or cramps and UK clinical guidance from NICE also advises not to use them for this purpose”. Do not stop a statin without talking to your GP first. Our cholesterol blood test guide explains the numbers a statin is there to move.
Helvy's General Energy & Wellness panel (£149) carries TSH, free T4, vitamin B12, vitamin D, magnesium, cortisol and CRP from a home finger-prick sample. Our energy and fatigue hub walks through what each one tells you.
CoQ10 itself is not on any Helvy panel. A blood test measures biomarkers and offers wellness insight. It does not diagnose the cause of your tiredness, and a qualified clinician reads the results in context.
Frequently asked questions
Is 100 mg of CoQ10 a day enough?
Nobody can say. There is no agreed effective dose, and 100 mg sits inside the 30 mg to 400 mg range that trials have used. It is a common starting point rather than a proven one.
Can you take too much CoQ10?
Side effects reported in trials are usually mild, such as trouble sleeping or an upset stomach. There is no UK upper limit set for it. Stay on the label dose and check with your doctor if you take any medicine.
When is the best time of day to take CoQ10?
With a meal that contains some fat, because that is how your gut absorbs it. Many people pick breakfast, since trouble sleeping is one of the reported side effects.
Does ubiquinol need a smaller dose than ubiquinone?
No published chart converts one to the other. A 2026 trial in 12 adults found one ubiquinol capsule absorbed about twice as well, but no trial shows either form eases tiredness better.
How long before CoQ10 works?
Longer courses did better than short ones in the pooled trials. Think in months. If you feel no different after that, it is a useful answer too.
READY TO TEST?
Start with the causes you can measure
The usual suspects behind tiredness sit on one home finger-prick panel. The quiz will tell you whether it fits your question. Results in around 5 working days from UKAS-accredited UK laboratories.
Related guides
Does CoQ10 Help With Tiredness?
What 13 trials found, and what to check before you buy.
Statins, Muscle Aches and CoQ10
Why most statin muscle pain is not the drug.
Always Tired? The Blood Tests Worth Doing
The common causes of tiredness a blood test can check.
Which Supplements Are Worth Taking?
The evidence, supplement by supplement.
Related panels
Keep reading