There are two primary forms of Coenzyme Q10 (CoQ10) found in the body and in supplements: ubiquinone and ubiquinol.
For decades, the only form of CoQ10 widely available as a supplement was ubiquinone, the oxidized form. This was largely due to manufacturing limitations. Although ubiquinol, the reduced and biologically active form of CoQ10, was identified as early as 1957, it is highly sensitive to light and air and was difficult to stabilize. Advances in formulation technology eventually solved this problem, allowing stabilized ubiquinol supplements to become commercially available around 2006.
How Do the Two Forms Differ?
Ubiquinone is the oxidized (inactive) form of CoQ10.
Ubiquinol is the reduced (active) form that the body uses directly.
Your body naturally produces ubiquinone and then converts it into ubiquinol. In young, healthy individuals, this conversion process is generally efficient. However, research shows that beginning around age 30, the body’s ability to both produce CoQ10 and convert ubiquinone into ubiquinol begins to decline. Chronic illness, oxidative stress, and certain medications can further impair this conversion.
This is where supplementation becomes especially important.
Because ubiquinol does not require conversion, it is immediately available for cellular use. This allows the body to more efficiently benefit from CoQ10’s roles in energy production and cellular protection. Only the ubiquinol form functions as a powerful antioxidant, helping protect cells from oxidative damage.
Notably, more than 90% of the CoQ10 found in the plasma of healthy individuals exists in the reduced ubiquinol form, underscoring its biological importance.
Potency and Cost Considerations
Most products labeled simply as “CoQ10” contain ubiquinone, as it is less expensive to manufacture. Ubiquinol typically costs more, but it is also significantly more potent and bioavailable.
Clinical evidence suggests that substantially lower doses of ubiquinol may achieve plasma CoQ10 levels comparable to much higher doses of ubiquinone. In practical terms, this often means better absorption, greater retention in the bloodstream, and more consistent results.
Dosage Considerations
For example, 150 mg of ubiquinol may be roughly equivalent to 1,200 mg of ubiquinone in terms of plasma CoQ10 levels.
Several studies—including those involving patients with congestive heart failure (CHF)—have shown that individuals often fail to achieve adequate plasma CoQ10 levels when using ubiquinone, but experience marked improvements when switched to ubiquinol.
It is important to note that dosages used in clinical trials—especially in critically ill patients—are often higher than typical over‑the‑counter recommendations. Therefore, CoQ10 supplementation should always be discussed with a healthcare provider.
Typical use ranges (not medical advice):
- Individuals over age 40, or those with suspected CoQ10 depletion due to illness or medication use, may consider starting with 200–300 mg of ubiquinol per day.
- Studies indicate that plasma CoQ10 levels tend to plateau after approximately two weeks at this dosage.
- A maintenance dose of 100 mg per day is often sufficient thereafter.
If you are pregnant, breastfeeding, or under medical supervision, consult your physician before beginning any supplement.
Another important distinction between the two forms is how long they remain active in the body. Research has shown that ubiquinol maintains nearly four times higher blood concentrations than ubiquinone eight hours after ingestion, suggesting superior bioavailability and retention.
Ubiquinol Research Highlights
Clinical trials have examined ubiquinol’s effects in a wide range of conditions, including:
- Cardiovascular disease
- Oxidative stress and aging
- Parkinson’s disease
- Diabetes
- Liver and kidney dysfunction
- Oral health
Among these, congestive heart failure (CHF) has been the most extensively studied.
In a landmark clinical trial, cardiologist Dr. Peter Langsjoen evaluated late‑stage CHF patients who were switched from ubiquinone to ubiquinol. After just three months, patients experienced a 24–50% improvement in cardiac pumping capacity compared to their results while taking ubiquinone. In some cases, plasma CoQ10 levels more than tripled.
At the beginning of the study, all participants had a life expectancy of less than six months. By the end of the trial, every patient demonstrated improved heart function and survived well beyond initial expectations.
Study abstract:
http://www.ncbi.nlm.nih.gov/pubmed/19096107
A Special Note for Statin Users
Statins are among the most commonly prescribed medications worldwide and are frequently used to lower cholesterol levels. These drugs work by inhibiting a key liver enzyme involved in cholesterol production.
Importantly, this same enzymatic pathway is responsible for the body’s production of CoQ10.
As a result, while statins may successfully reduce cholesterol, they often reduce circulating CoQ10 levels. This becomes particularly concerning when considering that CoQ10 deficiency may impair heart muscle energy production.
For this reason, many physicians now recommend CoQ10 supplementation—particularly ubiquinol—for patients taking statin medications.
Until next time, stay healthy!
Yours in health,
Dr. Gregg Gittins
