Does CoQ10 help with sleep, or cause insomnia? What the research does and doesn't show

The evidence doesn't support CoQ10 as a sleep aid, and it doesn't show that CoQ10 causes insomnia: we found no trial that tested either as its main question. Two small trials in people with other conditions measured sleep as a secondary outcome. Here is what they found, and where they fall short.

What the evidence doesn't support

It doesn't support CoQ10 as a treatment for insomnia or poor sleep, in any form or at any dose. It doesn't show that CoQ10 causes insomnia either: the safety review we read doesn't list it, but no study we read looked for it, so that is an absence of evidence rather than proof of safety. And it doesn't show that the time of day you take it changes your sleep: no trial we read tested that.

What the trials found

Safety review. A 2006 risk assessment of the published ubiquinone literature, written by the Council for Responsible Nutrition (an industry trade body), reported that nausea and other gastrointestinal effects were no more common at 1,200 mg a day than at 60 mg, and set an observed safe level of 1,200 mg a day. Its abstract doesn't mention sleep or insomnia (Hathcock 2006). A group-level review like this can't rule out an individual reaction.

Age-related tinnitus, 100 mg. A double-blind trial in 50 people with tinnitus due to age-related hearing loss gave 100 mg of CoQ10 or placebo daily, on top of routine treatment, for six weeks. A sleep-disturbance score changed by -7.60 in the CoQ10 group versus -1.0 on placebo (P < 0.001), with tinnitus disability also lower. Quality of life did not differ significantly. Sleep was one of four outcomes, in people whose sleep was affected by tinnitus, so it says little about sleep in other people. The abstract doesn't state the form (Abbasi 2025).

ME/CFS, 200 mg plus NADH. A 12-week trial in 207 people with myalgic encephalomyelitis/chronic fatigue syndrome gave 200 mg CoQ10 plus 20 mg NADH or placebo. Within the treatment group, sleep duration (at 4 weeks) and habitual sleep efficiency (at 8 weeks) changed from baseline (p = 0.018 and 0.038). The abstract reports no comparison with placebo for sleep, the CoQ10 was combined with another compound, and a co-author's employer funded the work, so it can't be read as an effect of CoQ10 alone (Castro-Marrero 2021).

Both trials were in people with a condition that disrupts sleep. Neither tested CoQ10 in people with ordinary sleep trouble, and neither tested whether it disrupts sleep.

Questions people ask

Can CoQ10 cause insomnia?

We found no study showing that it does, and none that tested the question. The side effects the safety review discussed were stomach-related. If you notice trouble sleeping after starting any supplement, stop and ask a pharmacist or doctor; see CoQ10 side effects.

Does CoQ10 affect sleep?

Two trials measured sleep in people with other conditions, with the limits above. No trial we read tested its effect on sleep in people without those conditions.

Does CoQ10 help with sleep, or help you sleep?

Not shown. The tinnitus trial's sleep result and the ME/CFS within-group changes don't establish it as a sleep aid, and neither is a trial of sleep problems.

Does the time of day I take CoQ10 matter for sleep?

No trial we read tested that. For what is known about timing and absorption, see the best time to take CoQ10.

When to talk to a doctor

Trouble sleeping that lasts more than a few weeks, loud snoring with daytime sleepiness, or sleeplessness alongside low mood needs a clinician, who can find the cause. CoQ10 is not a treatment for insomnia or any sleep disorder. If you take prescription medicine, ask your prescriber before adding a supplement.

Related reading: CoQ10 side effects, the best time to take CoQ10, CoQ10 dosage.