PQQ and Reported Side Effects

The data for PQQ’s safety is excellent, at least for limited or short-term use (e.g. up to a year) in humans and longer-term use in animals. Long-term (multiple year) safety in humans remains to be assessed.  However, based on pyrroloquinoline quinone direct to market sales, it may be concluded that hundreds of individuals now take PQQ.  Some of these users tend to be aggressive about supplementation (including myself), so the chance that an interaction with PQQ may be adverse seems highly unlikely based on the lack of any published reports.

Although there are no direct studies on the potential interaction of PQQ with psychotropic drugs, several studies suggest that the idea is worth exploring.  What data that are available regarding cognition are in two animal studies and one human study (see below). The human study is well controlled and the results of the study suggest that PQQ alone or with CoQ10 may be useful for improving higher brain function. Likewise, the animal studies are supportive of this perspective.

To be very clear, not all these supplements and medicines work independently? The best answer about food supplementation and drug interaction is going to come from your personal physician and pharmacist. Although one can identify major mechanisms or even specific functions for given compounds, from a global physiological perspective, there can be cross talk between the numerous cell-signaling pathways that control cellular function and an enzyme cofactor may interact with numerous enzymes each with a specific function.

1: Takatsu H, Owada K, Abe K, Nakano M, Urano S. Effect of vitamin E on learning and memory deficit in aged rats. J Nutr Sci Vitaminol (Tokyo). 2009; 55:389-93.

2: Ohwada K, Takeda H, Yamazaki M, Isogai H, Nakano M, Shimomura M, Fukui K, Urano S. Pyrroloquinoline Quinone (PQQ) Prevents Cognitive Deficit Caused by Oxidative Stress in Rats. J Clin Biochem Nutr. 2008; 42:29-34.

3: Pyrroloquinoline quinone disodium salt improves higher brain function.  Medical Consultation and New Remedies 2011; 48(5): 519 – A Japanese food/supplement journal


Aleta Lane

I’ve been reading information on PQQ and found it fascinating enough to want to try it for my own health… especially now that I’m past the half century mark! I see that Functional offers VitaPQQ at a discounted price of 20% off. What’s the difference between VitaPQQ and BioPQQ? Also, how many are in the bottle? Thanks!

Michael Rucker

Hi Aleta, the main difference is the dosage and the brand. BioPQQ is from Life Extension and VitaPQQ is from Quality of Life. Also, VitaPQQ is double the strength. Does that answer your question?


So BioPQQ and VitaPqq are the exact same chemical as PQQ?


Aleta, BioPQQ is a trademarked patented raw material of PQQ and both Life Extension and Quality of Life use it as their source of PQQ.

Sue Overfelt

Is PQQ safe if you have kidney disease?


Wondering if PQQ supplements would contraindicate with my husband’s blood pressure medication? And, which PQQ should I buy? Please reply.

Michael Rucker

There should not be any issues, but I would still ask your pharmacist and prescribing physician for their option to play it safe. I do not specifically endorse a particular brand of PQQ. If you purchase your supplements from a reputable supplier you should be okay.