Snooze University

Does CoQ10 Cause Insomnia? Here's What the Science Says

by Dale Cudmore | Updated: Jan 20, 2023

Coenzyme Q10 (CoQ10) shows potential at improving neurological aging, heart disease, diabetes, fertility, migraines, and more.

And while it’s generally well tolerated, some studies have had patients who report it causing insomnia.

There’s especially a risk to anyone taking CoQ10 if they are already taking other medications like blood thinners, antidepressants, or chemotherapy drugs (1). Consult a doctor before starting to supplement CoQ10.

Common Side Effects of CoQ10

The most common side effects of CoQ10 reported in research studies are (2):

Additionally, there are some reports of other uncommon side effects including (3):

  • Dizziness
  • Light sensitivity
  • Irritability
  • Headache
  • Fatigue
  • Insomnia

Of course, having headaches or being irritabile could indirectly lead to sleep trouble.

These symptoms are uncommon, and in most people, CoQ10 actually improves symptoms of insomnia (4).

How Likely Are Side Effects From Taking CoQ10?

Just how uncommon are side effects?

One study found (5):

Coenzyme Q10 was safe and well tolerated at dosages of up to 1200 mg/d.

Another study found that with a daily CoQ10 dosage of 50-150 mg, just 1.5% of patients experienced adverse effects (4).

Should I Take CoQ10 in The Morning or Night?

Not too much research has looked specifically at the time of ingestion.

However, what limited data there is points to insomnia being more likely if you take it close to bedtime (6).

In general, it’s best to take CoQ10 in the morning or afternoon to reduce the risk of side effects.

Should CoQ10 Be Taken With Food?

CoQ10 is fat soluble, meaning that it’s stored within fat in your body.

Fat soluble substances are typically best absorbed when consumed alongside food that contains some fat in it.

And finally, be aware that not all forms of CoQ10 are equal. The ubiquinol form of CoQ10 is the most absorbable (7).


  1. Interactions of commonly used dietary supplements with cardiovascular drugs: a systematic review
  2. Coenzyme Q10 effects in neurodegenerative disease
  3. Coenzyme Q10 (PDQ®)
  4. Italian multicenter study on the safety and efficacy of coenzyme Q10 as adjunctive therapy in heart failure
  5. Effects of coenzyme Q10 in early Parkinson disease: evidence of slowing of the functional decline
  6. Coenzyme Q10
  7. Increased bioavailability of ubiquinol compared to that of ubiquinone is due to more efficient micellarization during digestion and greater GSH-dependent uptake and basolateral secretion by Caco-2 cells

Medical Disclaimer: The information on is not intended to be a substitute for physician or other qualified care. We simply aim to inform people struggling with sleep issues about the nature of their condition and/or prescribed treatment.

About the authorDale is the founder of Snooze University and a sleep researcher. I overcame my sleep issues and now I'd like to help you do the same by summarizing the latest sleep studies for you.