Coenzyme Q10 — CoQ10 for short — is one of those nutrients that sounds complicated but does something beautifully simple: it helps every cell in your body make energy. It sits at the heart of a process called the electron transport chain inside your mitochondria, and without adequate CoQ10, your cells cannot produce ATP — the molecule that powers virtually everything you do, from breathing to thinking to recovering after exercise.
Here in Ireland, CoQ10 has become increasingly relevant for one very specific reason: cardiovascular disease remains the leading cause of death in Ireland, and a large proportion of Irish adults over 50 are now on statin medications to manage cholesterol. What many GPs do not routinely discuss — though the evidence is solid — is that statins significantly deplete CoQ10 levels. This guide explores the science, the Irish context, and what Pat Coffey at The Honey Pot in Clonmel has found to work best for his customers.
Your mitochondria are often called the "powerhouses of the cell," and CoQ10 is the indispensable shuttle that carries electrons between the protein complexes of the mitochondrial inner membrane. Without sufficient CoQ10, Complex I and Complex II cannot hand their electrons to Complex III, the chain stalls, and ATP production drops.
This matters enormously for tissues with the highest energy demands: the heart, the brain, the liver, and skeletal muscle. The heart muscle in particular never rests — it beats around 100,000 times a day — and cardiac tissue has among the highest concentrations of CoQ10 in the body. When those concentrations fall, heart function can be measurably compromised.
CoQ10 also functions as a fat-soluble antioxidant. In its reduced form (ubiquinol), it scavenges free radicals in cell membranes and in LDL cholesterol particles, protecting them from oxidative damage. This dual role — energetics and antioxidant defence — is what makes CoQ10 so uniquely important.
The good news is that humans produce CoQ10 endogenously. The bad news is that production peaks in your twenties and then steadily declines. By age 50 you may have 30–40% less CoQ10 in heart tissue than you did at 20. By 80, levels can be half what they were at peak.
The biosynthesis pathway for CoQ10 is long and complex — it requires over a dozen enzymatic steps and depends on adequate supplies of tyrosine, mevalonate (the same precursor used in cholesterol synthesis), and multiple B vitamins including B6 and B12. If any of these precursors are limited, CoQ10 output suffers.
Diet contributes modestly. The richest food sources are organ meats (liver, kidney, heart), oily fish, beef, pork, and nuts — all of which contain meaningful amounts. However, the quantities achievable through diet alone rarely compensate for age-related decline, and cooking destroys a significant fraction of dietary CoQ10.
This is the section that Pat Coffey at The Honey Pot discusses most often with customers. Statins — medications such as atorvastatin, simvastatin, and rosuvastatin — work by blocking HMG-CoA reductase, the enzyme that produces mevalonate. Mevalonate is required not only for cholesterol synthesis but also for CoQ10 synthesis. Block mevalonate, and you block both.
The clinical consequence is measurable. A 2015 meta-analysis in Nutrition Reviews found that statin use significantly reduced plasma CoQ10 concentrations. The more potent the statin and the higher the dose, the greater the depletion. Atorvastatin 80mg has been shown to reduce CoQ10 by up to 54% in some studies.
This may help explain one of statins' most common side effects: myopathy, or muscle pain and weakness, which affects up to 10% of statin users. Several randomised controlled trials have found that CoQ10 supplementation (100–300mg daily) significantly reduces statin-associated muscle symptoms, though guidelines from some cardiology bodies have been cautious about making blanket recommendations pending larger trials.
From a practical standpoint, Pat advises customers who are on statins to strongly consider a CoQ10 supplement — not to replace the statin, but to compensate for the depletion it causes. This is entirely consistent with available evidence and is routinely recommended by nutritional medicine practitioners across Ireland and the UK.
Beyond the statin connection, CoQ10 has a long research history in cardiovascular medicine. The landmark Q-SYMBIO trial published in 2014 in JACC Heart Failure followed 420 patients with severe heart failure for two years, comparing CoQ10 (300mg/day) to placebo. The CoQ10 group had significantly fewer major adverse cardiovascular events and a significantly lower all-cause mortality rate. These are the sorts of hard endpoints that impress cardiologists.
Earlier research, including work by Karl Folkers at the University of Texas, found that CoQ10 levels are consistently low in patients with all grades of heart failure, and that supplementation improves ejection fraction — the measure of how much blood the heart pumps with each beat. A 2018 Cochrane review found moderate-quality evidence that CoQ10 supplementation improves exercise tolerance and quality of life in heart failure patients.
For those without heart disease, CoQ10 may help maintain healthy blood pressure. Several meta-analyses have found modest but consistent reductions in systolic and diastolic pressure in CoQ10 supplementation studies, likely related to improved vascular endothelial function.
CoQ10 exists in two main forms: ubiquinone (the oxidised form) and ubiquinol (the reduced, active antioxidant form). All CoQ10 in the body cycles between these two states — ubiquinol is converted to ubiquinone as it donates electrons to the transport chain, and then reduced back to ubiquinol by antioxidant systems.
Ubiquinol has higher oral bioavailability in most studies — particularly in older adults, where the conversion from ubiquinone to ubiquinol appears to be less efficient. For people under 40 with reasonably healthy antioxidant status, standard ubiquinone is absorbed adequately and is considerably cheaper. For people over 50, those on statins, or anyone with chronic illness, ubiquinol is generally worth the premium price.
Look for CoQ10 in oil-based softgel capsules rather than dry powder tablets — CoQ10 is fat soluble and requires dietary fat for absorption. Taking your CoQ10 capsule with a meal containing healthy fats (e.g. avocado, olive oil, oily fish) will significantly improve uptake.
There is no official RDA for CoQ10 in Ireland or the EU, since it is not classified as an essential nutrient. Typical supplemental doses used in clinical trials range widely:
CoQ10 is well tolerated with a low side effect profile. Rarely, mild digestive upset occurs at high doses. There are no known serious adverse effects. Because CoQ10 can have mild anticoagulant properties, those on warfarin should discuss supplementation with their GP before starting.
A randomised controlled trial published in Neurology in 2005 found that CoQ10 at 300mg/day reduced migraine frequency by 47.6% versus 14.4% for placebo. Migraine is thought to involve mitochondrial dysfunction in susceptible neurons, which may explain why CoQ10 helps. Pat recommends this to several customers at The Honey Pot who have found it transformative for chronic migraine.
The mitochondria in sperm flagella depend on CoQ10 for motility. Multiple trials have found that CoQ10 supplementation (200–300mg/day for 3–6 months) improves sperm count, motility, and morphology in men with idiopathic infertility. For couples struggling with unexplained male-factor infertility, this is a low-risk, well-evidenced intervention worth discussing with a fertility specialist.
Athletes and active people use CoQ10 to support mitochondrial function and reduce exercise-induced oxidative damage. A review in the Journal of the International Society of Sports Nutrition found CoQ10 reduced exercise fatigue and accelerated recovery. These effects are more pronounced in older athletes and those with suboptimal CoQ10 status.
"CoQ10 is one of those supplements where I see really consistent results from customers," says Pat Coffey, who has run The Honey Pot health food store at 14 Abbey Street, Clonmel for over 40 years. "People who come to me on statins and are suffering from muscle aches — I nearly always suggest CoQ10, and the feedback is very positive. I tell them to take it with their main meal, in a good oil-based capsule, and not to buy a cheap dry-powder tablet. The quality of the product really matters with CoQ10."
The Honey Pot stocks a range of quality CoQ10 supplements and Pat is available for in-store consultations Monday to Saturday. The store ships Ireland-wide through thehoneypotonline.ie with free delivery on orders over €55.
The CoQ10 market in Ireland includes excellent products and some very poor ones. Here is Pat's checklist: