Benefits
Mitochondrial biogenesis (laboratory evidence)
PQQ activates PGC-1α and Nrf2 transcription factors that drive the production of new mitochondria — a process called mitochondrial biogenesis. That signalling work comes from cells and animals. No human trial cited here measured endurance, exercise capacity or metabolic efficiency.
Cognitive function and memory
Two 12-week randomised placebo-controlled trials of PQQ disodium salt, at 20 to 21.5 mg a day, reported gains in memory and attention. One showed clear improvements against placebo in adults averaging about 70; the other reported memory gains at 12 weeks in adults aged 20 to 65 without stating a placebo comparison in its abstract. Both were run by or with people tied to PQQ manufacturers, and neither measured fatigue. Improvements in cerebral blood flow and neuronal energy metabolism are proposed mechanisms.
Antioxidant activity in laboratory tests
In test tube chemistry PQQ can be reduced and re-oxidised many times over without being used up — a property that marketing turns into a claim that PQQ beats vitamin C. Two antioxidants that work in different parts of the cell cannot be ranked by counting cycles, and no head to head comparison has been run in people.
Nerve growth factor signaling (laboratory work)
In cultured cells, PQQ increases NGF (nerve growth factor) synthesis and secretion, supporting neuronal survival, neurite outgrowth, and synaptic plasticity. This has been seen in cell and animal work only. It has not been shown in people taking PQQ, and it is not a treatment for any nerve or brain condition.
Mechanism of action
PGC-1α activation and mitochondrial biogenesis
PQQ activates PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha) — the master regulator of mitochondrial biogenesis. PGC-1α upregulation triggers expression of genes involved in building new mitochondria. This pathway has been mapped in cells and rodents; it has not been measured in human tissue after supplementation.
Catalytic redox cycling
Unlike classical antioxidants that are consumed in neutralizing free radicals, PQQ undergoes repeated oxidation-reduction cycles in laboratory assays — continuously regenerating its antioxidant capacity. This catalytic mechanism is enabled by PQQ's quinone chemical structure.
CREB signaling and NGF synthesis
PQQ activates cAMP response element-binding protein (CREB), which drives NGF gene transcription in neuronal cells. NGF supports the survival and function of cholinergic neurons critical for memory, learning, and cognitive function.
Clinical trials
Randomized, double-blind, placebo-controlled trial of PQQ disodium salt (BioPQQ, 20 mg/day) for 12 weeks in 41 healthy elderly volunteers. (Adv Exp Med Biol — Itoh Y et al. 2016, 876:319-325, PMID 26782228)
41 healthy elderly volunteers.
The trial measured selective attention with the Stroop test and visual-spatial function with a tablet task. The change in Stroop interference was significantly smaller with PQQ than with placebo, which the authors read as better selective attention. On the tablet task the improvement appeared only in a subgroup with low baseline scores, not in the group as a whole. Composite memory was not measured in this trial. Critical caveat: small trial; industry-funded (Mitsubishi Gas Chemical, the major PQQ manufacturer). Effect sizes modest; independent peer-reviewed validation limited.
No indexed publication is cited for this card. The PQQ plus CoQ10 comparison comes from a Japanese manufacturer report (Koikeda T, Nakano M, Masuda K, Medical Consultation and New Remedies 2011;48:519-527) that is not indexed in PubMed and cannot be checked here; the summaries that do circulate describe 24 weeks of supplementation, not 12, and they disagree with each other on the number of participants and on the CoQ10 dose.
Healthy older adults.
The circulating summaries report better word memory with PQQ and with PQQ plus CoQ10, and better attention scores only in the combination group. None of that can be checked against a paper we can link, so treat it as a manufacturer claim rather than as evidence, and remember that a result from a combination says nothing about PQQ on its own.