Short answer. Coenzyme Q10 (CoQ10) is a fat-soluble compound the body makes itself and uses to produce cellular energy. It has no RDA or upper limit. A typical diet supplies only 3 to 6 mg a day (PMID 20301015), while studies use 100 to 200 mg, and safety evidence is strong up to 1,200 mg a day (PMID 16814438).
CoQ10 from food and in studies at a glance
| Source or study | Who | Daily amount and duration | What was reported |
|---|---|---|---|
| Usual diet, Pravst 2010 review (PMID 20301015) | General population | 3 to 6 mg a day from food | About half arrives in the reduced form (ubiquinol) |
| Weber 1997 (PMID 9266531) | Healthy adults, Denmark | One 30 mg dose, as a meal or as capsules | Blood levels rose similarly with both; diet supplied 3 to 5 mg a day, 64% from meat and poultry |
| Langsjoen 2014 (PMID 27128225) | 12 healthy volunteers | 200 mg of each form for 4 weeks, with a washout between | Plasma CoQ10 rose from 0.9 to 2.5 mcg/mL on ubiquinone and to 4.3 mcg/mL on ubiquinol |
| Zhang 2018 (PMID 30302465) | 10 older men | 200 mg with a main meal for 2 weeks per form | Ubiquinol raised total CoQ10 significantly; ubiquinone's rise was not significant |
| Engelsen 2003 (PMID 12772396) | 24 adults on long-term warfarin | 100 mg for 4 weeks | INR and warfarin dose stayed stable under close monitoring |
| Hathcock 2006 safety review (PMID 16814438) | Many clinical trials pooled | Up to 1,200 mg a day | Observed safe level 1,200 mg a day; stomach upset no more common than at 60 mg |
Source: PubMed abstracts listed under Sources.
What does CoQ10 do in the body?
Coenzyme Q10, also called ubiquinone, is a fat-soluble, vitamin-like molecule found in the membranes of every cell. The body makes it, and a smaller amount comes from food. Its best-known job is inside mitochondria, the structures that turn food into usable energy: CoQ10 passes electrons along the respiratory chain, a step the cell needs to produce ATP, its energy currency (NIH StatPearls, PMID 30285386).
CoQ10 has a second role as a fat-soluble antioxidant. It switches back and forth between two states. Ubiquinone is the oxidized form, and ubiquinol is the reduced form. The molecule works by accepting and donating electrons, so both forms are part of the same cycle (PMID 30302465). According to the NIH National Center for Complementary and Integrative Health (NCCIH), the highest levels in the body are in the heart, liver, kidneys and pancreas.
Is there a daily requirement for CoQ10 for children and adults?
No. CoQ10 does not appear in the US Dietary Reference Intake tables, so there is no Recommended Dietary Allowance, Adequate Intake or upper limit for any age, or for pregnancy or breastfeeding. Because the body makes its own supply, no official intake target has been set. The table below shows that gap next to vitamin E, the nutrient most often paired with CoQ10 in supplements.
| Age | CoQ10 RDA or AI | CoQ10 upper limit | Vitamin E RDA | Vitamin E upper limit |
|---|---|---|---|---|
| 1–3 years | Not established | Not established | 6 mg | 200 mg |
| 4–8 years | Not established | Not established | 7 mg | 300 mg |
| 9–13 years | Not established | Not established | 11 mg | 600 mg |
| 14–18 years | Not established | Not established | 15 mg | 800 mg |
| Adults 19 and older | Not established | Not established | 15 mg | 1,000 mg |
| Pregnancy | Not established | Not established | 15 mg | Same as for age |
| Breastfeeding | Not established | Not established | 19 mg | Same as for age |
Source: NIH Office of Dietary Supplements (vitamin E fact sheet) and the Dietary Reference Intake summary tables on NCBI Bookshelf. Vitamin E is in mg of alpha-tocopherol; 1 IU of the natural form equals 0.67 mg.
Can you get enough CoQ10 from food?
Food supplies some, but not much. A review of food analyses found that meat, fish, nuts and some oils are the richest sources, with much lower amounts in most dairy foods, vegetables, fruits and grains. The average diet provides only 3 to 6 mg a day, and the content of the same food varies widely depending on where it comes from (PMID 20301015).
The CoQ10 in food is absorbed. In a Danish study, the usual diet supplied 3 to 5 mg a day, 64% of it from meat and poultry. When healthy adults took a single 30 mg dose either in a meal or as capsules, blood levels rose significantly, and the peak levels did not differ between the two (PMID 9266531). Food and supplements work in very different ranges, though: the doses used in studies are 100 to 200 mg, far more than any ordinary diet provides.
Ubiquinone or ubiquinol: which form of CoQ10 is better?
Both are the same substance in different states, and the body converts one into the other all the time. About 95% of the CoQ10 circulating in blood is already ubiquinol, and that share stays about the same after a supplement is taken (PMID 17482886).
Two small head-to-head studies favored ubiquinol for raising blood levels. In the first, 12 healthy volunteers took 200 mg a day of ubiquinone for 4 weeks, stopped for 4 weeks, then took 200 mg a day of ubiquinol for 4 weeks, in identical softgels. Plasma CoQ10 rose from 0.9 to 2.5 mcg/mL on ubiquinone and from 0.9 to 4.3 mcg/mL on ubiquinol, and no side effects were noted (PMID 27128225). In the second, a double-blind crossover in 10 older men taking 200 mg a day with a main meal, ubiquinol raised total plasma CoQ10 from 1.3 to 3.4 umol/L in 2 weeks, while the rise on ubiquinone was not significant (PMID 30302465).
These results need context. Both studies were tiny and short. In the second one, 6 of the 10 men responded more to ubiquinol, but 2 responded more to ubiquinone, and neither form changed CoQ10 inside blood cells or the markers of energy and oxidative stress that were measured. Most of the published research on CoQ10 used ubiquinone. A reasonable approach is to start with well-absorbed ubiquinone taken with food and ask the doctor about a blood test if the question of absorption matters.
How should you take CoQ10 so it is absorbed?
CoQ10 is fat-soluble and does not mix easily with water-based foods (PMID 20301015), so the way it is taken matters. Practical points from the research:
- Take it with a meal that contains some fat. In the older-men study the doses were taken with a main meal (PMID 30302465), and CoQ10 eaten as part of a meal was absorbed as well as capsules (PMID 9266531).
- Prefer an oil-based or solubilized form. Solubilized formulas of both ubiquinone and ubiquinol produced higher blood levels (PMID 17482886).
- Large single doses are absorbed less efficiently. Blood levels rise as the dose goes up, but the share absorbed falls as the dose gets larger, and with one chewable tablet levels leveled off at 2400 mg (PMID 17482886).
- Time of day is flexible. The link is to food, not to morning or evening. NCCIH lists trouble sleeping as a possible mild side effect, so a person who notices this can take it earlier in the day.
Is CoQ10 safe, and how much is too much?
CoQ10 has a good safety record. NCCIH reports that no serious side effects have been reported, and mild effects such as digestive upset or trouble sleeping may occur.
Because there is no official upper limit, the most useful reference is a 2006 risk assessment of the clinical trials. Its authors concluded that the evidence of safety is strong at intakes up to 1,200 mg a day, which they called the observed safe level. Nausea and other stomach complaints were no more common at 1,200 mg a day than at 60 mg, so they could not be tied to CoQ10 itself. Higher amounts have been tested without harm, but the data above 1,200 mg a day are not enough for a confident conclusion (PMID 16814438). The products in this article supply 50 to 100 mg per serving, well below that level.
The sources used here give no data on CoQ10 in pregnancy or breastfeeding, so that decision belongs with the doctor or midwife.
Does CoQ10 interact with warfarin, statins or other medicines?
Warfarin. NCCIH notes that CoQ10 may interact with the blood thinner warfarin. Case reports have described a weaker warfarin effect after CoQ10 was started. In a controlled crossover trial, 24 adults on stable long-term warfarin (median age 64.5) took 100 mg of CoQ10 a day for 4 weeks; with INR kept between 2.0 and 4.0, the INR stayed stable and the weekly warfarin dose was essentially unchanged, 36.5 mg on CoQ10 and 36.0 mg on placebo (PMID 12772396). Even so, anyone on warfarin should tell the prescriber before starting CoQ10 so INR checks can be planned.
Insulin. NCCIH lists insulin as a medicine CoQ10 may interact with. People who use insulin should ask the prescriber first.
Statins. Statins are taken to lower cholesterol, and they also lower blood CoQ10. A meta-analysis of 8 placebo-controlled treatment arms found that statins lowered plasma CoQ10 by 0.44 umol/L. The drop appeared with all 4 statins studied (atorvastatin, simvastatin, rosuvastatin and pravastatin) and in trials both shorter and longer than 12 weeks (PMID 26192349). Whether that drop matters is less clear, and NCCIH says the overall evidence does not support CoQ10 for muscle pain caused by statins. Never stop or change a statin without the prescriber.
Other treatments. NCCIH notes that CoQ10 may not be compatible with some types of chemotherapy, so anyone receiving it should ask their care team first.
Can children take CoQ10?
There is no official intake level for children, and the clinical studies in this article were done in adults. Whether a child needs a CoQ10 supplement at all, and how much, is a question for the pediatrician. Among the products below, one label gives directions for children 4 years or older; the others either give no children's dose or say to follow a healthcare professional.
Which ASDHelp products contain CoQ10?
Doses are copied from each label. There is no upper limit for CoQ10, and every serving below is far under the 1,200 mg observed safe level. If you use more than one, add up the total. MITOboost and Spectrum Neurotransmitter Support list ubiquinone on the label, and the Coenzyme Q10 + E 100 product description names ubiquinone as well.
- Coenzyme Q10 + E 100: 100 mg of coenzyme Q10 per softgel, with vitamin E 64 mg (from 100 IU as d-alpha tocopherol) in an oil base. Label directions: 1 softgel a day; no children's dose. The vitamin E amount is below the upper limit for every age group and below the 400 IU a day that NIH ODS links to bleeding risk with blood thinners.
- MITOboost: 50 mg of coenzyme Q10 (ubiquinone) per 4 capsules, with acetyl-L-carnitine, NAC, alpha-lipoic acid and creatine. Label directions: adults, 4 capsules daily with food; children only as directed by a healthcare professional.
- Spectrum Neurotransmitter Support: 50 mg of coenzyme Q10 (as ubiquinone) per scoop (about 17.9 g), with NAC, DHA and phosphatidylserine. Label directions are for children 4 years or older, 1 level scoop in a drink; check with the pediatrician first.
Related reading: vitamin E, NAC and R-lipoic acid, other antioxidant nutrients found in these formulas.
Questions to take to your doctor
- Is a CoQ10 supplement useful for us at all, given that the body makes its own?
- Do any of our medicines, such as warfarin, insulin or a statin, change whether CoQ10 is a good idea or call for extra blood tests?
- If CoQ10 makes sense, what daily total from all products is right, and should we start with ubiquinone or ubiquinol?
- For a child, is any CoQ10 needed, and what amount fits their age and weight?
Sources
- Sood B, Patel P, Keenaghan M. Coenzyme Q10. StatPearls, NCBI Bookshelf (NIH), 2024. ncbi.nlm.nih.gov/books/NBK531491 (PMID 30285386)
- NIH National Center for Complementary and Integrative Health. Coenzyme Q10. nccih.nih.gov/health/coenzyme-q10
- NIH Office of Dietary Supplements. Vitamin E fact sheet for health professionals. ods.od.nih.gov/factsheets/VitaminE-HealthProfessional
- National Academies. Dietary Reference Intakes summary tables (NCBI Bookshelf). ncbi.nlm.nih.gov/books/NBK545442
- Pravst I, Zmitek K, Zmitek J. Coenzyme Q10 contents in foods and fortification strategies. Crit Rev Food Sci Nutr 2010. PMID 20301015
- Weber C, Bysted A, Hølmer G. Coenzyme Q10 in the diet: daily intake and relative bioavailability. Mol Aspects Med 1997. PMID 9266531
- Bhagavan HN, Chopra RK. Plasma coenzyme Q10 response to oral ingestion of coenzyme Q10 formulations. Mitochondrion 2007. PMID 17482886
- Langsjoen PH, Langsjoen AM. Comparison study of plasma coenzyme Q10 levels in healthy subjects supplemented with ubiquinol versus ubiquinone. Clin Pharmacol Drug Dev 2014. PMID 27128225
- Zhang Y et al. Ubiquinol is superior to ubiquinone to enhance coenzyme Q10 status in older men. Food Funct 2018. PMID 30302465
- Hathcock JN, Shao A. Risk assessment for coenzyme Q10 (ubiquinone). Regul Toxicol Pharmacol 2006. PMID 16814438
- Banach M et al. Statin therapy and plasma coenzyme Q10 concentrations: a systematic review and meta-analysis of placebo-controlled trials. Pharmacol Res 2015. PMID 26192349
- Engelsen J et al. Effect of coenzyme Q10 and Ginkgo biloba on warfarin dosage in patients on long-term warfarin treatment: a randomized, double-blind, placebo-controlled crossover trial. Ugeskr Laeger 2003. PMID 12772396; English report, Thromb Haemost 2002. PMID 12083489
These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease. This article is educational and is not medical advice.