PQQ (Pyrroloquinoline Quinone)

PQQ (Aka methoxatin) is a molecule with potent antioxidant and other beneficial properties. It can be found in green tea and many foods including; dark chocolate, spinach, celery, kiwi, parsley, green peppers, kiwi, soybeans, natto and human breastmilk.

Whilst there is currently little definitive human research on PQQ, it's claimed possible health benefits include;

Anti-inflammatory properties
Stimulation of mitochondrial biogenesis¹
Increased energy levels
Improved memory, attention and learning (aka a Nootropic)²
Neuroprotection
Immunoprotection
Improved sleep
Longevity - as a secondary benefit of those above but also in other areas such as inhibiting age-related intervertebral disk degeneration in mice³

There is some scientific debate that PQQ should be considered a vitamin.

Forms/Types

Usually supplied as pyrroloquinoline quinone disodium salt.

Quality

As with all supplements - buyer beware. It's quite common for supplements to be contaminated with a variety of impurities, often in the form of heavy metals, and/or contain far more or less of the ingredients stated on the label. There's no simple rule of thumb to avoid this, such as avoiding cheap or imported products; expensive or well-known brands produced in-country may be just as bad. Ideally you should take some time to find products (if you can) that;

have been laboratory tested on behalf of the manufacturer by a reputable body or company that operates in your country or region (here's an example of a Peak Supps creatine supplement available on Amazon in the UK which has been tested by Eurofins: Creatine Monohydrate Powder 1Kg | Pure Micronised | Packaging May Vary - see pictures 3 & 4)
have been laboratory tested by an independent testing company that ranks product purity and ingredient amount accuracy on behalf of consumers (usually funded by affiliate sales of those products). An example of this is Labdoor.

Dosage - How Much?

I can't find any scientific research that specifies a safe dosage for humans. In the UK, most supplements contain 20mg.

Deficiency - Too Little

Again, there is little available research but we found a review paper⁴ that states the following:

Although PQQ is not biosynthesized in mammals, trace amounts of PQQ have been found in human and rat tissues because of its wide distribution in dietary sources. Importantly, nutritional studies in rodents have revealed that PQQ deficiency exhibits diverse systemic responses, including growth impairment, immune dysfunction, and abnormal reproductive performance.

Toxicity - Too Much

Causes kidney damage in rats if taken in high doses⁵. The researchers found 100mg per kg of bodyweight a day was safe.

Side Effects

None reported that we can find.

When to Avoid Use - Interactions/Contraindications

Unknown.

Random Facts

Discovered by Jens Gabriel Hauge in 1964
Water soluble