Coenzyme Q10, also known as CoQ10, is a naturally occurring compound that plays an important role in energy production and antioxidant protection in the body. CoQ10 supplements have become popular to support heart health, boost energy levels, and provide antioxidant benefits.
While CoQ10 supplements are generally well tolerated, there are some individuals who should use caution or avoid taking them altogether. Here we will explore who should not take CoQ10 supplements.
Those with Allergies or Sensitivities
Like any supplement, CoQ10 may cause allergic reactions or sensitivity in some individuals. Symptoms like rash, itching, swelling, trouble breathing, or tightness in the chest may indicate an allergy.
People who are allergic to coenzyme Q10 itself or any components in a CoQ10 product should avoid supplementation. CoQ10 supplements often use oils like soybean, canola or olive oil. Allergies to these ingredients would warrant caution.
Those who have allergies or sensitivities may be able to tolerate topical forms of CoQ10 applied to the skin rather than ingesting the supplement.
People Taking Statins
Statins are a class of cholesterol-lowering medications that work by reducing the activity of HMG-CoA reductase, an enzyme involved in cholesterol synthesis. This has the effect of lowering cholesterol levels.
However, statins also block the natural synthesis of CoQ10 because it shares the same biochemical pathway. It’s estimated that statin use can lower CoQ10 levels by up to 40%.[1]
To counteract this depletion, it would seem reasonable for statin users to take CoQ10 supplements. However, some research has found that CoQ10 may interfere with the lipid-lowering effects of statins.[2]
Based on these findings, people taking statins should talk to their doctor before taking CoQ10 supplements. They may recommend temporarily discontinuing statins or reducing the dosage while supplementing with CoQ10.
Individuals Taking Warfarin
Warfarin is a blood-thinning medication used to prevent blood clot formation. It works by inhibiting vitamin K-dependent clotting factors.[3]
Some research indicates that CoQ10 may interfere with warfarin’s action, potentially increasing the risk of clot formation.[4] It’s thought that CoQ10 may activate vitamin-K dependent proteins, counteracting warfarin’s effects.
Given the serious health risks of blood clots, individuals taking warfarin should avoid CoQ10 supplementation unless approved by their healthcare provider. Close monitoring of blood clotting markers is recommended in this scenario.
Pregnant or Breastfeeding Women
Very little research has evaluated the safety of CoQ10 supplementation during pregnancy or breastfeeding.
Animal studies indicate that CoQ10 crosses the placenta and is excreted in breast milk.[5] The effects of supplemental doses on fetal and infant development are unknown.
Therefore, pregnant or breastfeeding women should avoid CoQ10 supplementation unless advised by their healthcare practitioner. Additional clinical studies in these populations are needed.
Those with Low Blood Pressure
Some evidence suggests that CoQ10 may help lower blood pressure, especially in those with hypertension.[6]
By improving the function of blood vessels and increasing nitric oxide production, CoQ10 supplements seem to have a mild blood pressure-lowering effect.
Consequently, those with normal or already low blood pressure should use CoQ10 with caution as it may cause blood pressure to drop too low. Monitoring of blood pressure is advised if supplementing.
Individuals Taking Antidepressants
Monoamine oxidase inhibitors (MAOIs) are a class of antidepressants that work by inhibiting monoamine oxidase, an enzyme that breaks down neurotransmitters like serotonin.[7]
There is some concern that CoQ10 may interfere with MAOI action. This is because MAOIs prevent the breakdown of tyramine-containing foods, which can trigger dangerous side effects like severely high blood pressure when combined with tyramine.
While the interaction is not well documented, those taking MAOIs like phenelzine (Nardil) and tranylcypromine (Parnate) should avoid CoQ10 supplements to be safe unless approved by a doctor.
Individuals Taking Hypoglycemic Medications
Some research indicates that CoQ10 may aid in lowering blood sugar levels, at least in those with diabetes.[8] This is believed to be related to CoQ10’s role in energy production and antioxidant effects.
Therefore, CoQ10 supplementation may enhance or amplify the effects of diabetes medications that lower blood sugar. Combining the two could potentially lead to dangerously low blood glucose.
Those on medications like insulin or sulfonylureas to manage blood sugar should use caution with CoQ10 and monitor glucose levels closely to avoid hypoglycemia.
People with CoQ10 Depletion Disorders
Certain rare genetic disorders like CoQ10 deficiency and ataxia with CoQ10 deficit directly affect the body’s synthesis of CoQ10.[9]
In these cases, CoQ10 supplementation is often used therapeutically to help restore adequate tissue levels. Excessively high doses may end up causing adverse effects in these populations.
Those with CoQ10 deficiency disorders should work with their healthcare provider to determine safe and appropriate CoQ10 dosage.
Conclusion
For most people, CoQ10 supplements are considered very safe, even at higher dosages. However, some special populations like those on certain medications, pregnant women, or individuals with chronic medical conditions may need to exercise caution.
It’s best to talk to your doctor before taking CoQ10 if you have any underlying health condition or take any routine medications. Your doctor can help determine if CoQ10 is appropriate and monitor for any potential interactions or side effects.
With the right precautions, most people can safely take advantage of the health-promoting properties of CoQ10. As with any supplement, it’s wise to start slow and follow dosage recommendations to minimize side effects.
References
1. Marcoff L, Thompson PD. The role of coenzyme Q10 in statin-associated myopathy: a systematic review. J Am Coll Cardiol. 2007 Jun 12;49(23):2231-7.
2. Young JM, Florkowski CM, Molyneux SL, McEwan RG, Frampton CM, Nicholls MG, Scott RS, George PM. Effect of coenzyme Q(10) supplementation on simvastatin-induced myalgia. Am J Cardiol. 2007 Nov 1;100(9):1400-3.
3. Ansell J, Hirsh J, Hylek E, Jacobson A, Crowther M, Palareti G; American College of Chest Physicians. Pharmacology and management of the vitamin K antagonists: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest. 2008 Jun;133(6 Suppl):160S-198S.
4. Engelsen J, Nielsen JD, Winther K. [Effect of coenzyme Q10 and Ginkgo biloba on warfarin dosage in stable, long-term warfarin treated outpatients. A randomised, double blind, placebo-crossover trial]. Ugeskr Laeger. 2002 May 20;164(21):2968-71.
5. Teran E, Hernandez I, Nieto B, Tavara R, Ocampo JE, Calle A. Coenzyme Q10 supplementation during pregnancy reduces the risk of pre-eclampsia. Int J Gynaecol Obstet. 2009 Apr;105(1):43-5.
6. Rosenfeldt FL, Haas SJ, Krum H, Hadj A, Ng K, Leong JY, Watts GF. Coenzyme Q10 in the treatment of hypertension: a meta-analysis of the clinical trials. J Hum Hypertens. 2007 Apr;21(4):297-306.
7. Youdim MB, Edmondson D, Tipton KF. The therapeutic potential of monoamine oxidase inhibitors. Nat Rev Neurosci. 2006 Mar;7(3):295-309.
8. Hodgson JM, Watts GF, Playford DA, Burke V, Croft KD. Coenzyme Q10 improves blood pressure and glycaemic control: a controlled trial in subjects with type 2 diabetes. Eur J Clin Nutr. 2002 Nov;56(11):1137-42.
9. Quinzii C, Lopez LC, Gilkerson RW, Dorado B, Coku J, Naini AB, Lagier-Tourenne C, Schuelke M, Salviati L, Carrozzo R, Santorelli F, Rahman S, Tazir M, Koenig M, DiMauro S, Hirano M. Reactive oxygen species, oxidative stress, and cell death correlate with level of CoQ10 deficiency. FASEB J. 2010 Oct;24(10):3733-43.
Who Should Not Take CoQ10?
While CoQ10 supplements are generally considered safe, there are some groups who should use caution or avoid supplementation altogether:
Individuals with Allergies
Those allergic to CoQ10 itself or ingredients like soybean oil should avoid supplements due to potential allergic reactions.
People Taking Statins
CoQ10 may interfere with statins’ cholesterol-lowering effects. Those on statins should consult their doctor before supplementing.
People Taking Warfarin
CoQ10 may decrease warfarin’s effectiveness as a blood thinner. Close medical supervision is recommended if taking both.
Pregnant or Breastfeeding Women
Insufficient data exists on CoQ10 supplementation during pregnancy/breastfeeding. Caution is advised.
Those with Low Blood Pressure
CoQ10 may further lower blood pressure. People with hypotension should monitor their blood pressure if supplementing.
Individuals Taking MAO Inhibitors
CoQ10 may interfere with MAOI antidepressants. Those taking MAOIs should avoid supplementation.
People Taking Hypoglycemic Medications
CoQ10 may enhance the blood sugar-lowering effects of diabetes medications. Frequent glucose monitoring is recommended.
Those with CoQ10 Deficiency Disorders
Individuals with CoQ10 deficiency may require precise CoQ10 dosing determined by their doctor. Excessively high doses may be harmful.
Who Can Safely Take CoQ10?
When taken under the right conditions and dosage, CoQ10 is safe for most people. Some individuals who can safely take CoQ10 include:
Healthy Adults
Most healthy adults can safely supplement with up to 200 mg per day of CoQ10. Higher doses around 400 mg may be used under medical supervision.
Older Adults
Aging adults can benefit from CoQ10 supplementation to support heart health, energy levels and antioxidant status. Doses up to 200 mg per day are typically recommended.
Those with Heart Conditions
Patients with heart failure, angina or myocardial infarction may see therapeutic benefits from taking 100-300 mg per day of CoQ10 under medical care.
Individuals with Neurodegenerative Disorders
CoQ10’s antioxidant effects may help conditions like Parkinson’s disease and Huntington’s disease. Doses around 300-1200 mg divided into several doses may be used under supervision.
Migraine Sufferers
CoQ10 supplementation appears to reduce migraine frequency. Doses of 100-400 mg per day in divided doses are commonly used.
Those on Psychiatric Medications
Certain psychiatric meds like lithium and Valproic acid may deplete CoQ10. Doses around 90-200 mg per day may help counteract this.
People with Mitochondrial Disorders
Primary CoQ10 deficiencies are mitochondrial disorders that may benefit from high-dose supplementation under medical guidance.
Athletes
CoQ10’s role in energy production may benefit physical performance. However, optimal doses are still under investigation.
Key Considerations When Taking CoQ10
Here are some key considerations regarding the safe use of CoQ10 supplements:
- Discuss with your doctor, especially if taking medications or have a medical condition
- Start with low doses and gradually increase if needed
- Divide daily dose into 2-3 smaller doses
- Take with food to enhance absorption
- Look for products containing ubiquinol (the active form)
- Avoid high doses over 400 mg unless medically advised
- Monitor for side effects like diarrhea, nausea, rash or low blood pressure
- Allow 2-3 months to see benefits due to CoQ10’s accumulation in tissues
The Bottom Line
CoQ10 is a generally safe nutritional supplement that may provide health benefits. However, certain medical conditions and medications warrant caution with CoQ10 use due to potential side effects or interactions.
It’s wise for those on any routine drugs or with underlying health conditions to talk to their doctor before taking CoQ10. With medical guidance, most people can safely take CoQ10 supplements.
