PQQ (Pyrroloquinoline Quinone) Review: Clinical Facts You Don’t Know

Update 10/3/24. Does PQQ work? That's the question somebody asked me. What's PQQ, you ask? PQQ stands for Pyrroloquinoline quinone, and it's one of the most popular health supplements today. In this PQQ review, you'll learn about its health benefits and PQQ clinical research. Special emphasis will be placed on human research and the dosages used in research. This is important because it will help you figure out if it's right for you. Side effects will also be discussed. Do you need pyrroloquinoline or is it a scam? Let's see.

What Is PQQ?

Without getting too bogged down in the science, pyrroloquinoline quinone (PQQ) is an antioxidant compound found in foods (see below). It plays a role in cell signaling. In other words, PQQ helps cells talk to each other. It also seems to play a role in many different cellular processes, most notably helping the growth of mitochondria, the powerhouses of our cells. Another name for this substance is methoxatin although this word is seldom used.

Contrary to popular opinion, pyrroloquinoline quinone is not a vitamin.  At best, it's vitamin-like.

How Do You Pronounce It?

The two words in the name are pronounced Pie-rello-quin-a-leen  Quin-own. Now say that three times really fast 🙂

PQQ Benefits

Various studies have hinted pyrroloquinoline quinone may have a wide range of health benefits such as:

1. Brain Health
2. Heart health
3. Diabetes health
4. Mitochondria health
5. Anti-inflammation effects
6. Anti-aging effects
7. Boosts metabolism
8. Cholesterol-lowering effect

And other things. In the sections below, we'll focus on the PQQ evidence for these benefits. If you know the evidence, you will know if pyrroloquinoline quinone is right for you.

Do We Make This Stuff?

Research suggests that some strains of gut bacteria can make PQQ, but the amount is pretty small. Most of what we get comes from foods and supplements.

Foods With PQQ

Pyrroloquinoline quinone is found in many foods. Here's a brief list, along with the dosages.

Food	PQQ Amount
Fermented soy (natto)	61 ng/g
Green tea	29.6 ng/g
Parsley	34.2 ng/g
Green peppers	28.2 ng/g
Oolong tea	27.7 ng/g
Kiwi	27.4 ng/g
Papaya	36.7 ng/g
Tofu	24.4 ng/g
Spinach	21.9 ng/g
Carrots	16.8 ng/g
Cabbage	16.3 ng/g
Sweet potatoes	13.3 ng/g
Bananas	12.6 ng/g
Tomatoes	9.2 ng/g
Bread	9.14 ng/g
Egg yokes	7 ng/g
Oranges	6.8 ng/g
Celery	6.33 ng/g
Apples	6 ng/g
Wine	5.8 ng/ml
Sake	3.6 ng/ml
Skim milk	2.5 ng/ml

Obviously there is not a lot of PQQ in foods. The letters “ng” mean nanograms. A nano-gram is 1 billionth of a gram. That's a VERY small amount. As you can see from the list of foods, fermented soy (natto) has some of the highest levels of PQQ, coming in at 61 nanograms per gram.

In other words, if you ate a gram of natto, you'd be getting about 61 billionths of a gram of PQQ. That's not a lot. Supplements contain a LOT more pyrroloquinoline quinone than foods, generally in the 10-30 mg range.

PQQ Research

There is a long list of things pyrroloquinoline quinone is supposed to help. Let's take a look at some of the most popular claims for this supplement and see what we can figure out.

PQQ and Heart Health

Lab animal research suggests that pyrroloquinoline quinone may help rats' hearts work better. When researchers deprived rats of PQQ, they had lower aerobic abilities, and the mitochondria in their heart cells didn't work well. This sounds promising, but what about people? Good question. Research on the effects of pyrroloquinoline quinone supplements on human hearts cannot be located. Still, this compound may be found in heart-healthy supplements because of evidence like this.

Does PQQ Lower Cholesterol?

Researchers in Japan gave pyrroloquinoline quinone supplements or a placebo to 29 older people with high cholesterol and triglyceride levels for 6-12 weeks. Taking supplements did not reduce triglyceride levels although there was a “marginally significant” reduction in average bad (LDL) levels. I don't consider this important because the LDL only dropped from 136 to 127.

This means their LDL levels were still “high.” Those with the highest LDL levels seemed to have the greatest reduction in LDL levels.

Compared to a placebo, The supplement used (BioPQQ) did not lower triglyceride levels.

See the Bergamot Review for more insights.

Does PQQ Reduce Inflammation

CRP (C Reactive Protein) is a substance which can tell doctors what your cellular inflammation is. Unhealthy, long term cell inflammation is thought to be at the center of many diseases.

At least one human study has noted PQQ supplements can reduce inflammation. This was a small study consisting of only 10 people. There was no placebo group either.

PQQ And The Brain

Can this substance help the brain function better? Researchers in Japan noted pyrroloquinoline quinone improved blood flow to the prefrontal cortex of the brain when it was given to 20 people for 12 weeks. The prefrontal cortex is involved in complex thinking processes like decision making and personality.

Other researchers have observed PQQ-raised levels of an antioxidant enzyme called superoxide dismutase (SOD) in the brains of mice. Theoretically, this could help older brains battle free radical damage. Some may take glutathione supplements because it also raises SOD levels.

Research like this may be why pyrroloquinoline quinone is of interest to those with dementia. It's intriguing, although there is no proof this means it helps Alzheimer's or other forms of dementia.

This study used a specific supplement called BioPQQ.

Here it is on Amazon

Rat studies suggest PQQ may help protect against strokes. So far, though, there is no direct human proof pyrroloquinoline quinone supplements reduce stroke risk in people.

There is also some interest that the supplement may help people with concussions and other forms of traumatic brain injury. While encouraging, the proof that it helps brain injury is preliminary and based mostly on lab animal evidence.

PQQ Memory Research Review

Watch on my YouTube channel

PQQ and Diabetes

Diabetes is the 7th leading cause of death in the US. Anything that can done to stabilize blood sugar and insulin levels will improve this health condition. At least one study has found PQQ reduces CRP levels. CRP is a marker of cell inflammation. Since diabetes increases cell inflammation, in theory, the supplement may help. But it will take human research to know for sure.

Currently, there is no good proof pyrroloquinoline quinone directly improves blood sugar levels or helps people with diabetes. To put things in perspective, there is far more evidence that taking a 20-minute walk improves blood sugar and insulin levels than taking pyrroloquinoline quinone supplements.

PQQ and Aging

Some may take this supplement hoping it will help slow down the aging process. While lab rat research hints it may improve mitochondria function in older mice, does it do the same thing in people?

Currently, no good proof pyrroloquinoline quinone supplements slow down or reverse the aging process in humans.

Does PQQ Raise Metabolism?

Metabolic rate refers to how many calories we burn for energy. Higher metabolic rates burn more calories and are often associated with weight loss. So, can PQQ supplements boost metabolic rate? Maybe in mice, but this is not known for people.

What About Weight Loss?

Can this supplement help you lose weight? This nutrient helps the mitochondria function better and may boost metabolism (in mice), so it stands to reason that it would help people lose weight.

It sounds good in theory. The problem is nobody has tested it yet. Pyrroloquinoline has been known to exist since the late 1970s. I'm quite surprised nobody had given it to people for a month or two to see if it helps weight loss.

Can It Help You Fall Sleep Faster?

One study suggested that pyrroloquinoline may help you sleep better. Researchers gave 20 people 20 mg of PQQ for 8 weeks. People completed surveys before and after the study. Results indicated the supplement seemed to improve a variety of things such as:

1. sleep quality
2. depression
3. confusion
4. anger/hostility
5. fatigue and anxiety

This study sounds great, except:

• There was no placebo group to compare the results to
• Everybody knew what they were getting (the study was not “blinded”)

This was a human study, so that's good. But, it needs to be replicated with a better investigation.

This study also involved the use of the BioPQQ supplement.

PQQ and Exercise

One of the ways we adapt to exercise is by making more mitochondria. Mitochondria are basically fat-burning batteries inside our cells. As we make more mitochondria, we become better at burning fat. The more mitochondria we have, the better we can perform aerobic exercise (running, walking, biking, etc).

Sometimes, athletes try to give themselves an advantage by training at higher altitudes. This causes them to make more red blood cells, which carry oxygen to the muscles.

When researchers in India exposed rats to higher altitudes, they observed the combination of pyrroloquinoline quinone  and curcumin improved the adaptions of rat hearts when the rats exercised at the higher altitudes. This has the potential to make them better “rat athletes.”

This is a very interesting finding. One problem is we can't tell if the benefits resulted from the combination of ingredients or curcumin or pyrroloquinoline alone.

So, if you're an athlete, will pyrroloquinoline quinone help you perform better? In theory, maybe, but I think it's too soon to know.

PQQ Human Research

Study 1. In one investigation, researchers gave 10 people a PQQ flavored drink. They observed the nutrient caused a slight but significant reduction in TBARS, a marker of free radical damage. This makes sense since it's an antioxidant. They also noted reductions in C reactive protein (CRP), a marker of inflammation.

The amounts used in this study were 0.2 mg/kg and 0.3 mg/kg. How much is that? If you weighed 180 pounds (82 kg), the dosage used was 16 mg to 25 mg. For reference, many PQQ supplements contain 10-30 mg per one to two capsules.

Study 2. At least one study has shown a supplement called BioPQQ improves blood flow to the prefrontal cortex of humans better than a placebo when taken for 12 weeks at a dosage of 20 mg per day.

Study 3. PQQ may slightly reduce LDL (bad cholesterol) levels in humans according to one investigation. The dosage used was 20 mg. This study also noted triglyceride levels may not be reduced.

Study 4. Pyrroloquinoline quinone may improve sleep as well as reduce anger, anxiety, depression, and hostility according to one small investigation which lacked a placebo group. The dosage used in this investigation was 20 mg.

Does It Prevent Disease?

This is the 64,000 question. So far, there is no human evidence the supplements prevent disease or reduce disease risk.  To be fair, this is a difficult problem to figure out. If you look at the preliminary evidence, the writing on the wall says, it might help. But, it's too soon to know for sure.

PQQ Vs. Tru Niagen

Nicotinamide riboside is a very popular anti-aging supplement. It's contained in a supplement called Tru Niagen as well other supplements too. Nicotinamide riboside is derived from the vitamin, niacin (vitamin B3). One of the things Niagen is touted to do raise NAD levels. NAD is a molecule involved in energy production. This helps our mitochondria work better and may, in theory, reduce the risk of disease.

Some research suggested PQQ can increase NAD levels too.

So, the logical question is whether PQQ is better than nicotinamide riboside. Which compound raises NAD levels the most?

Unfortunately, there are no direct comparisons between Niagen and pyrroloquinoline quinone to see which substance raises NAD levels best.

So nobody can say which nutrient is more healthy. Also, no no investigation has combined Niagen + pyrroloquinoline quinone together. Maybe the combination is better or not. It will take research to know for sure.

For more on TruNiagen see these reviews:

• Niagen review
• Elysium Basis Review
• My 30 Niagen experiment 
• NMN review

If raising NAD levels is something you want to do, watch this video I created on how to naturally raise your NAD levels

Watch video on YouTube

PQQ vs. CoQ10

Are pyrroloquinoline quinone supplements better than coenzyme Q10? Coenzyme Q10 (CoQ10), also called ubiquinol and ubiquinone is another very popular supplement that has been shown to have a variety of health effects.

Research has noted that CoQ10 supplementation appears to help:

• The heart
• the mitochondria 
• the eyes
• Fibromyalgia

and many other things.

Both compounds are called “quinones.” Because of this, supplement companies may combine both compounds together in the hopes of getting better results.

While, in theory, adding CoQ10 may bolster the effects of pyrroloquinoline quinone, proof for this is lacking.

One difference between these nutrients is when it comes to CoQ10, generally more is required, around 100 mg. Only 20-30 mg for pyrroloquinoline seems to be needed. Does that mean pyrroloquinoline is more potent than Coq10? Good question. I don't think anyone cay say which is better at this point.

One advantage of CoQ10 is there are a lot more human studies on it.

Here's a COQ10 brand I like

Where Do You Buy It?

You can purchase this supplement at local health food stores like Vitamin Shoppe and GNC. Amazon also has a wide selection to choose from. I did not see it at Target or Bed Bath and Beyond when I looked.

Many supplements cost between $20 and over $50 for a month's supply. There is no proof that more expensive brands are better than less expensive supplements.

How Much Do You Take?

Most supplements contain between 10 mg and 30 mg per one to two capsules. Several human trials have used 20 mg per day. When in doubt, start with the lower end of this range to see how you respond.

PQQ Side Effects

No harmful side effects have been reported in lab animal or human studies. So far there is no evidence it raises LDL like pterostilbene appears to or causes blood pressure or heart problems. Keep in mind pyrroloquinoline quinone is mostly studied in lab animals.

Here is a brief list of general suggestions before using this supplement. This list is not complete.

1. Start with less than is recommended for the first week to see how you respond.
2. Don't take if you are pregnant or nursing.
3. Speak to your doctor/pharmacist if you take medications like blood thinners.
4. If you have any health issues, speak to your doctor/pharmacist
5. If you have cancer, speak to your doctor before taking any antioxidant supplements
6. To avoid possible stomach upset, take with food
7. Stop taking the supplement at least 2 weeks before having surgery

At higher blood levels, PQQ has the potential to become prooxidant. In other words, PQQ can generate free radicals. This is true for all antioxidants also. All antioxidants can both neutralize and create free radicals. This is referred to as a REDOX reaction.

It's not known if pyrroloquinoline quinone supplements elevate free radicals in people.

Diabetics should talk to their doctor/pharmacist if they use glucose test strips which use PQQ to monitor blood sugar levels. Evidence suggests these types of blood sugar test strips may falsely indicate high blood sugar levels. This can result in insulin overdose. This does not mean PQQ supplements raise blood sugar levels. This only seems to be related to blood sugar test strips.

Does PQQ Work?

That's a good question, and I don't think anyone knows the answer right now. Most research involves lab animals. That doesn't mean the supplement doesn't do anything. Rather, it means scientists have some work to do to find out if it works and who may benefit from it. The preliminary evidence tells us the nutrient has interesting properties. For some, that's enough to start taking it now.

If you prefer to wait for more evidence, remember small amounts are found in foods. If you're eating those foods, you are already getting pyrroloquinoline quinone.

Here it is on Amazon

Any Comments or Questions?