PQQ Review – Benefits, Dosage, Sources and Side Effects Of Pyrroloquinoline Quinone


What Benefits Does Pyrroloquinoline Quinone Has To Offer?

Most people do not know about its existence. But some of those who do consider pyrroloquinoline quinone (PQQ) a worthy addition to your arsenal for promoting good health.


This is a relatively new substance, which researchers are only starting to know more about. You will find practically all you need to know about pyrroloquinoline quinone in this article, including purported benefits, sources and side effects.

What is Pyrroloquinoline Quinone?

PQQ is a vitamin-like compound present in many kinds of foods of plant origin. The small molecule was actually thought to be a vitamin in the past. But researchers now understand it to be a pseudovitamin.

Also known as methoxatin, this compound is regarded are a redox agent or co-factor. It helps to reduce oxidants and can be recycled back into active form by glutathione. Researchers think it’s potentially capable of undergoing several thousands of cycles before it is used up.

PQQ occurs both in the diet and tissue of mammals, including humans. Scientists view it as potentially being a bioactive, non-vitamin compound.

Your body produces it naturally from amino acids.

PQQ is a coenzyme in bacteria, in which it promotes growth. According to Examine, you may think of it more as a B-vitamin in these organisms.

The discovery of the tiny molecule has been credited to J. G. Hauge, who described it as naphthoquinone. It was isolated for the first time from methanol dehydrogenase of methylotrophs in 1979.

PQQ was initially found to be a cofactor in numerous enzymatic reactions in bacteria. Later research revealed that it had similar effects in many mammals.

Benefits of PQQ

Many health benefits have been associated to pyrroloquinoline quinone. But there seems to be no consensus among medical experts on some of these being convincing and well-proven.

Most of the positive studies done so far were in animals. Some experts argue that the observed benefits may not necessarily apply to humans.

In any case, let’s consider some of the known benefits of PQQ that are evidence backed.

Inflammation control

Chronic inflammation is at the root of many disorders, including diabetes and heart disease. As a result of its ability to reduce oxidants, PQQ may help control this problem. Its antioxidant properties can help to deal with free radicals that promote inflammation and cell damage.

In research that appeared in the Journal of Nutritional Biochemistry, researchers were able to show that supplementing with the compound led to significant improvements of multiple markers of inflammation. They observed these changes after only three days of supplementation!

Improvement of mitochondrial function

What research has probably shown more is the ability of PQQ to enhance mitochondrial function. It helps to boost production of more mitochondria while also boosting their efficiency.

Mitochondria are often described as the “powerhouse of the cells.” This is because they help to produce energy from glucose and oxygen.

It is for this reason that you will see PQQ as an ingredient in some energy drinks or supplements. The compound is often combined with others like CoQ10 in such products.

If you suffer mitochondrial inefficiency, some problems you may experience include muscle weakness, reduced growth, greater risk of infections, and gastrointestinal problems.

In the 2013 research by Harris and colleagues published in the Journal of Nutritional Biochemistry, it was found that PQQ enhanced mitochondria-related functions in animals [1].

Some researchers think that the compound probably enhances mitochondrial function by improving the expression of sirtuins, especially SIRT1 and SIRT3.

Prevention of oxidative stress

This benefit matters so much for aging in particular. Oxidative stress is believed to be associated to many issues seen in older people.

PQQ appears to alter oxidation in cells by binding to certain proteins. This, experts say, can influence the signaling processes that take place in cells. That can be a good thing.

The compound may not really be considered a real antioxidant. But it is able to exert antioxidant effect through interaction with the enzyme glutathione.

There are several studies suggesting that PQQ may help protect against oxidative stress and damage. In one by researchers at Japan’s Hokkaido University, it was shown to inhibit oxidative stress-related neuronal death.

Brain health and function enhancement

The ability of PQQ to help prevent oxidative stress makes it more likely to benefit your mental health. For instance, rodent models of Parkinson’s disease showed that the small molecule might have protective effect.

Research shows that this effect is attributable to improved mitochondrial efficiency and reduced oxidative stress. These helped to reduce the death of neuron cells.

Scientists have also observed that this compound may have a role to play in neurogenesis. Studies by some Japanese researchers showed that it led to dramatic surge in nerve growth factor (NGF) synthesis after 24 hours.

Evidence from animal studies suggests that PQQ may offer a boost to memory and learning. It has been shown to help fight memory declines that result from stress. It helped against memory impairment due to insufficient oxygen and damage resulting from methylmercury toxicity.

What this essentially means is that the molecule may help fight age-related memory decline.

Researchers were able to show in a 2016 study that PQQ can improve the flow of blood to the brain. This is capable of boosting the efficiency of the organ. It may, thus, help prevent issues such as dementia in older individuals.

What’s more? Researchers have been able to show that PQQ may be helpful for protecting against brain injury.

In a 2012 study published in the peer-reviewed Journal of Neurotrauma, scientists found that giving PQQ injections to rats for three days before a traumatic brain injury protected them against the effect. The extent of protection was best with the highest dose.

Obesity prevention

PQQ may offer some help against obesity, which has become a serious health threat. Research shows that the compound increases metabolic rate. This means it is potentially capable of helping to promote weight loss.

But there appears to be no human studies currently showing that it can prevent obesity. It is only a possibility, considering effect on metabolic rate.

Sleep aid

Apart from enhanced mitochondrial function, positive effect on sleep is one of the other benefits you’d likely see people associate with PQQ.

This benefit was proven in a 2012 study that appeared in the journal Functional Foods in Health and Disease (FFHD). The subjects, who suffered from fatigue or sleep-impairing disorder, were given PQQ (20mg) for a period of eight weeks. This improved both sleep duration and quality and reduced sleep latency – that is, how long it takes to fall asleep.

Heart health protection

PQQ may also help to safeguard your heart due to how it can help to reduce cholesterol levels. Although beneficial to health, having too much of this substance poses serious risk to health.

Too much cholesterol can clog blood vessels. This makes your heart to work harder to pump blood around your body. It increases your risk of heart attack.

Adults who took supplemental PQQ in one Japanese study were found to experience significant reduction in their “bad” cholesterol levels.

The compound has also been observed to lead to lower triglyceride levels in rats, compared to counterparts that were deficient.

Research suggests that PQQ might even be more potent than fish oil for reducing triglycerides. This again is thought to be linked to improved mitochondrial efficiency.

It could prove beneficial for combating atherosclerosis. Studies have shown that it reduces both C-reactive protein and trimethylamine-N-oxide (TMAO). These are considered to be biomarkers of the disorder.

Longevity promotion

You might have observed from the foregoing that PQQ may prove useful for living longer in good health. If it helps to control inflammation, improve mitochondrial function and fight oxidative stress, it is safe to assume the compound can promote longevity.

Researchers were able to show in a study involving roundworms that supplementing with this molecule helped to control oxidative stress and enhance life span.

PQQ may help protect you against age-related disorders, including Alzheimer’s disease and osteoporosis.

It could help with treatment of insulin resistance, especially the kind linked to fats. This it does by enhancing mitochondrial biogenesis in muscle cells, somewhat like physical exercise.

Being a non-vitamin growth factor, PQQ is helpful for promoting growth and development. Researchers are also investigating more on its potential to help epilepsy, convulsions, and ischemia, among others.

PQQ Dosage

It is obvious that pyrroloquinoline quinine has a lot to potentially offer for promoting good health. This might make you want to increase its intake. But how much of it do you take?

There is currently no standard for the amount a person needs to take daily. Doses as low as 2 mg have been used in animal studies.

However, you’d usually find dietary supplements offering 20 to 40 mg PQQ. Doses in this range are usually considered safe and efficacious.

You should consider starting at a low dose and increasing gradually, as you see necessary.

Sources of PQQ

Pyrroloquinoline quinone occurs naturally in soil. It is present in most foods, although usually in very low quantities.

If you desire to increase the amount in your diet, the following are some of the foods that offer the highest levels:

  • Fermented foods, such as natto or miso
  • Kiwifruit
  • Green soybeans
  • Parsley
  • Tofu
  • Green tea
  • Spinach
  • Rape blossoms (blossoms of the rapeseed plant)
  • Green pepper
  • Celery
  • Fava bean
  • Cabbage

PQQ can also be found in the human breast milk.

Estimates of how much of the compound you find in foods widely vary. Studies show that they can range from about 0.20 nanograms per gram (ng/g) to roughly 61 nanograms per gram.

With such low levels, it is not very certain that you will get many benefits, if any, from eating most foods containing PQQ. This explains why supplemental forms with much higher doses are used in studies.

But you may find consuming foods with the highest levels, such as fermented products, parsley, green peppers, green tea and tofu, to be more helpful.

You may support these foods with supplements. But make sure you only go for the very best.

Purchase products by reputable companies only. Offerings produced from fermented bacteria tend to be better than those synthetically made in a lab.

PQQ Side Effects

There shouldn’t really be any issue when consuming foods containing PQQ – maybe except if you have an allergy to such.

But you will have to exercise caution when using supplements. It is easier to overdose with these since they contain stronger forms of the compound.

Renal issues have been reported in rat studies from PQQ injections. At a dose of 11-12 mg per kg bodyweight in one study, the compound was linked to inflammation of kidney tubules.

Researchers observed that a 20mg/kg dose produced certain symptoms of renal and hepatic toxicity.

Deaths were reported in rats at 500mg or higher doses.

In humans, no serious side effects were reported from using PQQ (20 mg) alone or together with 300mg CoQ10 in one study. The treatment lasted for 12 weeks in that study.

Evidence from research seems to suggest that a 20mg dose might just be the most advisable. This especially applies if you are trying PQQ for the first time.

Common side effects from taking an overdose include fatigue, headaches and sleepiness. But extremely high doses can be potentially life-threatening.

Final Thoughts on PQQ

Pyrroloquinoline quinone has been shown to be potentially helpful in many ways. It may help you promote better sleep, fight oxidative stress, improve heart health, enhance mitochondrial, and increase energy levels.

Evidence of usefulness comes mostly from animal and test-tube studies. But some human studies have also been done to highlight its potential. Researchers are still studying several of the possible benefits.

It is safer to improve PQQ levels through consumption of foods that contain high amounts. Supplements may, however, offer the more effective means of raising levels.

Be careful when taking supplements to enjoy the supposed benefits, though. Make sure you buy only products by trusted and reliable companies. Also, ensure that you take no more than the dose that is recommended.

If you are pregnant or nursing, it may not be advisable to use this compound. This does not mean that it is unsafe, but it has not yet been studied for such situations. It is, therefore, better to play it safe or you talk to your doctor.

Do you know of any other interesting PQQ benefits that we didn’t mention in this article? Please let us know in the comment section.


Dietary pyrroloquinoline quinone (PQQ) alters indicators of inflammation and mitochondrial-related metabolism in human subjects. – PubMed – NCBI (https://www.ncbi.nlm.nih.gov/m/pubmed/24231099/)

Pyrroloquinoline quinone – Wikipedia (https://en.wikipedia.org/wiki/Pyrroloquinoline_quinone)

Pyrroloquinoline quinone: Proven Health Benefits, Dosage, and more | Examine.com (https://examine.com/supplements/pyrroloquinoline-quinone/)



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