Ubiquinone (CoQ10) & ubiquinol

The difference between ubiquinone and ubiquinol

Before jumping into the research, let’s do a quick review on the difference between ubiquinone and ubiquinol. Chemically, ubiquinol is the fully reduced form of CoQ10 known as CoQ10H2. This means that it has two additional hydrogens than standard, oxidized ubiquinone, which is also known as CoQ10. Most CoQ10 products on the market today provide ubiquinone, although it is ubiquinol that provides virtually all of benefits associated with CoQ10. This does not necessarily mean that supplementation with ubiquinol is necessary, however, since the human body can easily convert ubiquinone into ubiquinol. The fact is that supplementation with either ubiquinone or ubiquinol has value.

CoQ10 and semen

Previous research from 2004 showed that infertile men with idiopathic asthenozoospermia (the medical term for reduced sperm motility) who take 200 mg/day of CoQ10 had increased sperm motility after six months of treatment. Since low-seminal plasma concentrations of CoQ10 have been associated with some parameters of impaired sperm, researchers decided to further explore the relationship between semen and CoQ10.

A recent randomized, placebo-controlled study examined the effect of CoQ10 on catalase, superoxide dismutase (SOD) and F2–isoprostanes (prostaglandin-like compounds formed in the body from the free radical-catalyzed peroxidation of essential fatty acids) in seminal plasma in infertile men. Forty-seven infertile men with idiopathic oligoasthenoteratozoospermia (the medical term for semen with a low concentration of sperm) received 200 mg/day of CoQ10 or placebo for three months. Not surprisingly, the results showed that CoQ10 levels increased significantly following supplementation in CoQ10 (P < 0.001). In addition, the CoQ10 group had higher catalase and SOD activity than the placebo group. There was also a significant positive correlation between CoQ10 concentration and normal sperm form and structure (P = 0.037), catalase (P = 0.041) and SOD (P < 0.001). Furthermore, after supplementation there was a significant reduction in seminal plasma 8-isoprostane in the CoQ10 group compared to the placebo group (P = 0.003). The authors concluded that three-month supplementation with CoQ10 in oligoasthenoteratozoospermia infertile men can reduce oxidative stress in seminal plasma and improve semen parameters and antioxidant enzymes activity.

CoQ10 and fibromyalgia

In 2002, an open, pilot study found that supplementation with 200 mg/day of CoQ10 in conjunction with 200 mg/day of Ginkgo biloba extract for 84 days improved quality of life parameters in fibromyalgia patients, including physical fitness levels, emotional feelings, social activities, overall health and pain. The 2002 study did not, however, investigate the mechanism of action behind these beneficial effects. One possibility is that the mechanism had to do with the neurotransmitter, known as serotonin. The reason is that the relationship between serotonin in the pathophysiology of fibromyalgia has previously been explored, and medications that modulate serotonin levels are currently used in the treatment of fibromyalgia. Since serotonin is an important modulator of pain perception, sleep, fatigue, cognition and mood in normal subjects, this supports the positions that disturbances in these functions in fibromyalgia (e.g. fibromyalgia patients have higher levels of depression) can result of abnormalities in the content, metabolism or transmission serotonin.

Recent research set out to determine if CoQ10 had an impact on serotonin in fibromyalgia patients. A randomized, double-blind, placebo-controlled study examined the effects of 300 mg/day of CoQ10 (divided into three daily doses) on serotonin and depression in 20 fibromyalgia patients for 40 days. Ten patients received CoQ10 and 10 patients received a matching placebo. CoQ10 and serotonin levels were assessed using blood and blood platelet samples, and depression was evaluated the Beck Depression Inventory (BDI) scale. Results showed that CoQ10 and serotonin levels in platelets from fibromyalgia patients were restored in the CoQ10-treated group compared to placebo group. A significant improvement in depressive symptoms was also observed in the CoQ10-treated group compared to the placebo group (P < 0.001). In fact, the authors of the study stated, “Our findings also support the hypothesis that CoQ10 supplementation can be used as an alternative therapy for controlling depression.”

CoQ10, the Mediterranean diet and aging

Past research has shown that CoQ10 plays a role as a powerful antioxidant in cells, inhibiting lipid peroxidation in cell membranes and DNA, and is involved in helping to protect against different types of oxidative damage. A study in 2012 found that CoQ10 supplementation in combination with the Mediterranean diet in an elderly population reduces the inflammatory response and stress to those parts of the cell responsible for manufacturing proteins—which is important to help prevent aging-related disease such as diabetes, inflammation and neurodegenerative disorders, including Alzheimer’s disease. The question is, would CoQ10 and the Mediterranean diet help also help reduce DNA damage, which would be a boon to the aging population? This was explored in recent research.

In July of 2014, a new study was published in which 20 participants were randomly assigned to one of three groups for four weeks: 1) a Mediterranean diet supplemented with coenzyme Q10, 2) a Mediterranean diet alone, and 3) a saturated fatty acid-rich diet. Volunteers were then tested to determine if certain genes expressed themselves (the process by which information from a gene is used in the synthesis of a protein or RNA), which in this case would be an indicator of DNA damage. The results showed that those in the Mediterranean diet group, and especially those in Mediterranean diet supplemented with coenzyme Q10 group, experienced a reduction in the expression of the genes associated with increased DNA damage. The researched concluded that these results indicated a triggering of DNA repair machinery.

Ubiquinol and autism

Since autistic spectrum disorders can be associated with mitochondrial dysfunction and oxidative stress, and since CoQ10 is beneficial for treating both of these issues, this raised the question as to whether supplementation with CoQ10 would be helpful with autism. A case study published in 2006 did report a variety of improvements in an autistic girl treated with a program of vitamin supplements, L-carnitine and CoQ10, but this was insufficient for drawing conclusions for a larger population of autistic patients. However, a recent study took another look at this question.

Twenty-four children, aged 3-6 years, with autism were given 50 mg of ubiquinol twice daily for a total daily dose of 100 mg. Data on behavior of the children were collected from parents. The results were that supplementation with ubiquinol improved symptoms in children with autism, including:

• communication with parents (in 12 percent)
• verbal communication (in 21 percent)
• playing games of children (in 42 percent)
• sleeping (in 34 percent)
• food rejection (in 17 percent)

This is the first study in which beneficial effects of ubiquinol in children with autism has been demonstrated.


Supplementation with ubiquinone and ubiquinol has been shown in research to continue offering a range of benefits. Based upon research published in 2014, this includes reduction oxidative stress semen, a reduction of depression in fibromyalgia patients, reduction in the expression of the genes associated with increased DNA damage and improved symptoms in children with autism. 



Previous Next Back to Top
More Related Articles