PQQ Supplement Guide: Mitochondrial Support, Cognitive Benefits, and Clinical Evidence (2026)

What Is PQQ?

Pyrroloquinoline quinone (PQQ) is a redox-active quinone first identified as a cofactor for bacterial enzymes. It is not classified as a vitamin, but in animals it supports neonatal growth and reproductive performance, and its role in mitochondrial biogenesis has drawn interest for human health (Rucker et al., 2009).

PQQ was initially discovered in 1979 as a cofactor for bacterial dehydrogenase enzymes. Its role in mammalian biology took longer to establish, but research over the past two decades has revealed that PQQ activates critical signaling pathways involved in mitochondrial function, antioxidant defense, and neuroprotection.

As an antioxidant, PQQ can be reduced and re-oxidized repeatedly, which is why reviews describe it as a potent redox-active antioxidant with mitochondrial and neuroprotective properties (Xie et al., 2025).

PQQ occurs in small amounts in foods such as natto, green tea, parsley, kiwi fruit and green peppers. Those amounts are tiny compared with supplement doses; a 2024 review uses 20 mg/day as the reference supplemental intake (Ikemoto et al., 2024).

How PQQ Supports Mitochondrial Function

In cell studies, PQQ increased mitochondrial biogenesis by activating the transcription factor CREB and the coactivator PGC-1α (Chowanadisai et al., 2010). In young mice, PQQ deficiency altered mitochondrial quantity and function (Stites et al., 2006). These findings are the main reason PQQ is promoted for energy and brain health, but human mitochondrial data are limited.

Mitochondria are the energy-producing organelles in every cell. As we age, mitochondrial number declines, existing mitochondria accumulate damage, and energy production becomes less efficient. This mitochondrial decline is implicated in virtually every aspect of biological aging — from cognitive decline to heart failure to loss of muscle mass.

PQQ acts on PGC-1α, the master regulator of mitochondrial biogenesis. In cells, PQQ raised PGC-1α expression through CREB phosphorylation and stimulated the formation of new mitochondria (Chowanadisai et al., 2010).

PQQ also matters at the whole-animal level. Young mice on a PQQ-deficient diet had altered mitochondrial quantity and function (Stites et al., 2006), and in 20-month-old mice PQQ improved spatial working memory and recognition, effects linked to mitochondrial bioenergetics and a SIRT1-UCP2-associated pathway (Yan et al., 2026).

PQQ also activates the Nrf2 antioxidant response pathway, which upregulates endogenous antioxidant enzymes (SOD, catalase, glutathione peroxidase) and suppresses NF-κB-driven inflammation. This dual action, mitochondrial biogenesis plus antioxidant enhancement, is particularly relevant in the aging brain (Xie et al., 2025).

Clinical Evidence: Cognitive Function

Three randomized trials point to cognitive benefits. In 41 healthy older adults, 20 mg/day for 12 weeks limited the decline in Stroop test performance, a measure of attention (Itoh et al., 2016). In 64 healthy adults aged 40 to 79, 12 weeks of PQQ improved memory, attention, reaction time and cognitive flexibility (Shiojima et al., 2022). In older adults with mild cognitive impairment, a hydrogen-plus-PQQ blend for six weeks improved mental orientation (Baltic et al., 2024).

Healthy older adults. Forty-one healthy older adults took 20 mg/day of PQQ disodium salt or placebo for 12 weeks. The change in Stroop interference was significantly smaller with PQQ, and a preliminary near-infrared test suggested more blood flow in the prefrontal cortex (Itoh et al., 2016).

Middle-aged and older adults. Sixty-four healthy Japanese adults aged 40 to 79 took PQQ disodium salt or placebo for 12 weeks. The PQQ group improved on composite memory, verbal memory, reaction time, complex attention, cognitive flexibility, executive function and motor speed, and on the MMSE-J screening test, with no adverse events (Shiojima et al., 2022). A separate study summarized in a 2024 review found that cognitive flexibility and executive speed improved by eight weeks in adults aged 20 to 40 (Ikemoto et al., 2024).

Mild cognitive impairment. Thirty-four older adults with mild cognitive impairment took a dihydrogen-PQQ blend or placebo for six weeks. The blend improved mental orientation and brain metabolism markers, though the authors cautioned that the small sample limits interpretation (Baltic et al., 2024).

One important caveat: the Baltic trial used PQQ in combination with molecular hydrogen, so the individual contribution of PQQ cannot be fully isolated. However, the results are consistent with the earlier PQQ-only trials and with the mitochondrial biogenesis mechanism that would be expected to improve brain energy metabolism and oxygenation.

PQQ and Sleep Quality

Sleep data come from an open-label trial, which a 2024 review summarizes as showing better sleep and mood with PQQ (Ikemoto et al., 2024). Without a placebo group, those results are preliminary.

Open-label studies cannot separate a supplement's effect from expectation, so the sleep findings need a placebo-controlled test. A mitochondrial explanation would be plausible, since brain energy metabolism affects sleep regulation, but that link is speculative.

Mitochondrial dysfunction in the brain is increasingly recognized as a contributor to age-related sleep disruption. By supporting mitochondrial biogenesis in neural tissue, PQQ may address an upstream cause of poor sleep rather than simply providing symptomatic sedation, a fundamentally different approach than traditional sleep supplements.

PQQ + CoQ10: Synergistic Benefits

A 2024 review describes Japanese studies in which adding CoQ10 to PQQ further enhanced cognitive effects (Ikemoto et al., 2024). The animal data are less supportive: in rats, PQQ improved learning more than CoQ10, but combining the two did no better than PQQ alone (Ohwada et al., 2008). The pairing is reasonable but not proven to be synergistic.

The rationale is that the two act on different parts of mitochondrial function: PQQ signals the creation of new mitochondria (Chowanadisai et al., 2010), while CoQ10 carries electrons in the respiratory chain of existing ones. In theory they complement each other, but a larger combined effect has not been shown in a published placebo-controlled human trial.

The human claim of synergy rests on Japanese studies summarized in a 2024 review (Ikemoto et al., 2024). In the rat study, the combination did not improve learning beyond PQQ alone (Ohwada et al., 2008).

PQQ Dosage and How to Take It

The best-studied dose is 20 mg/day of PQQ disodium salt, used in the 12-week cognitive trial in older adults (Itoh et al., 2016). A 2024 review reports that 100 mg/day for 24 weeks was well tolerated in a human study (Ikemoto et al., 2024). Taking it with a meal is a reasonable default.

20 mg/day: the dose in the Itoh trial and the reference intake in Japanese research (Ikemoto et al., 2024). Morning or midday dosing is a reasonable choice.

10 mg/day: a common label dose and a reasonable starting point, though most trial data come from 20 mg.

Combination protocol: 20 mg PQQ with 100 to 300 mg CoQ10, taken with a meal. Japanese studies suggest added benefit (Ikemoto et al., 2024), but the rat data do not show synergy (Ohwada et al., 2008).

A 2024 review reports a human study in which 100 mg/day for 24 weeks caused no safety problems (Ikemoto et al., 2024), and the 12-week cognitive trial in adults aged 40 to 79 observed no adverse events (Shiojima et al., 2022).

Safety and Side Effects

PQQ has been well tolerated in trials: no adverse events were observed over 12 weeks in the Shiojima trial (Shiojima et al., 2022), and a 2024 review reports good tolerance at 100 mg/day for 24 weeks (Ikemoto et al., 2024). Drug interactions have not been studied.

Published trials have not reported a consistent pattern of side effects at the studied doses (Shiojima et al., 2022). As with any new supplement, stop if you notice persistent discomfort.

PQQ and Inflammation: The Nrf2-NF-κB Dual Switch

PQQ simultaneously activates the Nrf2 antioxidant pathway and suppresses NF-κB inflammatory signaling, a dual mechanism that coordinates anti-inflammatory and antioxidant responses. This bidirectional effect is particularly relevant for age-related neuroinflammation, which drives cognitive decline through chronic low-grade inflammation in the brain (inflammaging).

Chronic low-grade inflammation, termed "inflammaging", is now recognized as a central driver of age-related disease. In the brain, activated microglia release pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) that damage neurons, impair synaptic plasticity, and disrupt neurotransmitter signaling. This neuroinflammatory environment accelerates cognitive decline, reduces neurogenesis, and increases susceptibility to neurodegenerative diseases.

PQQ addresses neuroinflammation through two complementary pathways. First, it activates Nrf2 (nuclear factor erythroid 2-related factor 2), which translocates to the nucleus and upregulates the expression of many cytoprotective genes including heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductase 1 (NQO1), superoxide dismutase (SOD), catalase, and glutathione peroxidase. This enhanced endogenous antioxidant capacity neutralizes the reactive oxygen species that trigger and sustain inflammatory cascades.

Second, PQQ suppresses NF-κB — the master transcription factor for inflammatory gene expression. When NF-κB is inhibited, the production of pro-inflammatory cytokines, chemokines, and adhesion molecules is reduced. This suppression occurs at the level of IκBα phosphorylation, preventing NF-κB from translocating to the nucleus and activating inflammatory gene transcription.

Human data are limited but consistent. In a small study, PQQ lowered plasma C-reactive protein and IL-6, reduced urinary methylated amines such as trimethylamine N-oxide, and shifted urinary metabolites in a way consistent with better mitochondrial function; the authors described the data as among the first to link PQQ's animal effects to humans (Harris et al., 2013).

The 2025 review by Xie et al. positioned PQQ as a potential neuroprotective agent for neurodegenerative diseases specifically because of this dual anti-inflammatory/antioxidant mechanism. The authors noted that PQQ's ability to simultaneously enhance mitochondrial biogenesis (through PGC-1α), reduce oxidative stress (through Nrf2), and suppress neuroinflammation (through NF-κB) makes it a uniquely multi-targeted compound for brain health, addressing three of the four major hallmarks of neurodegeneration in a single molecule.

PQQ Food Sources and Dietary Intake

PQQ is present in trace amounts in many foods, including natto, green tea, parsley, kiwi fruit and green peppers. Dietary intake is far below the 20 mg/day used in supplement research (Ikemoto et al., 2024), so supplements are the only practical way to reach studied doses.

Unlike spermidine, where dietary intake can approach clinically relevant levels through food choices, PQQ concentrations in food are measured in nanograms per gram, three orders of magnitude lower than supplement doses. The gap between dietary intake and clinical doses is enormous:

Commercial supplements use PQQ disodium salt made by bacterial fermentation, the same form used in the main human trials (Itoh et al., 2016) (Shiojima et al., 2022).

The question of whether food-based PQQ provides meaningful health benefits at dietary intake levels (0.1–1.0 mg/day) is unresolved. Some researchers hypothesize that even trace dietary PQQ contributes to mitochondrial health over decades of consistent exposure, and that populations with higher PQQ-rich food consumption (e.g., Japanese diets high in natto and green tea) may derive cumulative benefits. However, no study has specifically evaluated health outcomes at dietary PQQ levels — the clinical evidence only supports effects at supplement doses of 10–20 mg/day.

PQQ vs. CoQ10 vs. NMN: Choosing the Right Mitochondrial Supplement

PQQ, CoQ10, and NMN all support mitochondrial health but through different mechanisms. PQQ creates new mitochondria (biogenesis). CoQ10 optimizes the electron transport chain in existing mitochondria (efficiency). NMN boosts NAD+ to fuel mitochondrial enzymes (fuel supply). The three are complementary, and combining PQQ with CoQ10 has clinical trial support showing superior cognitive outcomes versus either alone.

PQQ (pyrroloquinoline quinone). Primary mechanism: mitochondrial biogenesis through CREB and PGC-1α (Chowanadisai et al., 2010). It is the only one of the three studied mainly for increasing mitochondrial number. Dose: 20 mg/day in trials. Best for: adults interested in cognitive support with modest but growing trial data.

CoQ10 (ubiquinone/ubiquinol). Primary mechanism: electron carrier in Complex III of the mitochondrial electron transport chain. Optimizes ATP production efficiency within existing mitochondria. CoQ10 levels decline with age and are further depleted by statin medications. Dose: 100–300 mg/day (ubiquinol form is better absorbed). Best for: people on statins, those with heart failure or low energy, and as a complement to PQQ for complete mitochondrial support.

NMN (nicotinamide mononucleotide). Primary mechanism: NAD+ precursor. NMN is converted to NAD+ in cells, which serves as a cofactor for mitochondrial enzymes (particularly in Complex I) and fuels sirtuin-dependent repair pathways. NAD+ does not create new mitochondria or improve electron transport, it provides the fuel that mitochondrial enzymes need to function. Dose: 250–1,000 mg/day. Best for: broad anti-aging support, NAD+ restoration, sirtuin activation.

The logic of combining them is quantity (PQQ), efficiency (CoQ10) and fuel (NMN). Only PQQ plus CoQ10 has been studied, in Japanese research summarized in a 2024 review (Ikemoto et al., 2024), and the three-way combination has not been tested.

For budget-conscious supplement users: PQQ + CoQ10 is the best-supported two-supplement combination for mitochondrial health. Adding NMN expands the approach to include NAD+ restoration but increases cost significantly. Prioritize based on your primary concern: cognitive function → PQQ + CoQ10; overall aging → add NMN; statin use → CoQ10 first, then add PQQ.

Who Should Consider PQQ Supplementation?

PQQ is best suited for adults over 40 concerned about age-related cognitive decline, people seeking mitochondrial support beyond CoQ10 alone, and individuals experiencing fatigue, brain fog, or reduced mental sharpness that may relate to declining mitochondrial function. It is not a treatment for diagnosed neurological conditions, which require medical management.

Adults over 40 with early cognitive concerns. The clinical trials showing cognitive benefits enrolled participants aged 40–80, with the most pronounced effects in those experiencing age-related cognitive slowing. If you notice that mental tasks take longer, working memory feels less sharp, or multitasking is harder than it used to be, PQQ at 20 mg/day is a reasonable evidence-based intervention.

People already taking CoQ10. If you supplement CoQ10 for heart health or statin-related depletion, adding PQQ extends the mitochondrial support from optimizing existing organelles to creating new ones. The combination has clinical trial support and addresses a different aspect of mitochondrial health than CoQ10 alone.

NMN/NAD+ supplement users. If you are already investing in NAD+ restoration through NMN or NR, PQQ adds the mitochondrial biogenesis component that NAD+ precursors alone do not provide. More mitochondria means more sites for NAD+-dependent enzymes to work, potentially amplifying the benefits of NAD+ supplementation.

People with persistent fatigue or brain fog — While fatigue has many possible causes (and should be medically evaluated if persistent), mitochondrial dysfunction is an underrecognized contributor. PQQ's ability to stimulate new mitochondrial production can address cellular energy deficits that standard medical workups may not identify.

Who should not rely on PQQ: people with diagnosed neurodegenerative diseases (Alzheimer's, Parkinson's) should work with neurologists and not substitute supplements for proven medical therapies. PQQ is a preventive and health-maintenance supplement, not a treatment for established neurological disease.

PQQ and Exercise Performance

No published trial has shown that PQQ improves exercise performance. In a 2026 trial of 60 participants, 20 mg of PQQ improved one self-reported measure of interoception, body listening, after exhaustive exercise (Zhao et al., 2026), but performance itself was not the outcome.

Mitochondrial density in skeletal muscle is the key physiological determinant of aerobic exercise capacity. Elite endurance athletes have approximately twice the mitochondrial content of untrained individuals. Exercise training stimulates mitochondrial biogenesis through the same PGC-1α pathway that PQQ activates, raising the question of whether PQQ supplementation can enhance or accelerate exercise-induced mitochondrial adaptations.

The theoretical framework for PQQ in exercise is compelling: if exercise and PQQ both activate PGC-1α, combining them could produce additive mitochondrial biogenesis signals. Exercise provides the acute stimulus (transient AMPK activation during each workout), while PQQ provides a sustained baseline activation (continuous PGC-1α upregulation from daily supplementation). The result could be faster accumulation of new mitochondria and more rapid improvements in aerobic capacity during a training program.

However, this remains largely theoretical for exercise performance specifically. No published trial has used PQQ as an ergogenic aid in a training study with performance outcomes (VO2max, time to exhaustion, race performance). The exercise evidence is limited to metabolic biomarkers and subjective exertion measures. Athletes interested in PQQ for performance enhancement should consider it an emerging area of interest rather than an established ergogenic strategy, and prioritize proven training, nutrition, and recovery practices first.

For recreational exercisers and active adults over 40, the rationale is somewhat different. In this population, the goal is not peak performance but maintaining mitochondrial function and exercise capacity that naturally decline with age. PQQ's ability to stimulate new mitochondrial production addresses the age-related loss of mitochondrial density that contributes to declining exercise tolerance, slower recovery, and increased fatigue, making it potentially more relevant for aging athletes than competitive performers.

PQQ and Heart Health

PQQ has not been tested on heart outcomes in people. The rationale is indirect: heart muscle relies heavily on mitochondria, and in a small human study PQQ lowered CRP and IL-6, two inflammatory markers linked to cardiovascular risk (Harris et al., 2013).

The heart is among the most mitochondria-rich organs, reflecting the energy demands of constant contraction. When mitochondria decline, heart muscle produces less ATP, which contributes to age-related cardiac decline.

Mitochondrial damage builds up in heart cells over decades. The idea behind PQQ is that stimulating new mitochondria (Chowanadisai et al., 2010) could offset some of that loss, but this has not been tested in human hearts.

The Harris et al. (2013) human study provides indirect cardiac evidence: PQQ supplementation reduced CRP and IL-6 — both systemic inflammatory markers that are independent cardiovascular risk factors. While the trial did not measure cardiac function directly, the reduction in inflammatory biomarkers suggests a favorable cardiovascular risk modification profile.

For people concerned about age-related cardiovascular health, PQQ's mitochondrial biogenesis effects complement other established cardiac-supportive supplements. CoQ10 optimizes existing cardiac mitochondria, omega-3 fatty acids reduce inflammation and arrhythmia risk, and magnesium supports cardiac electrophysiology and vascular relaxation. PQQ adds the dimension of new mitochondrial production that none of these other supplements provide.

PQQ Absorption and Bioavailability

Human data show that oral PQQ is absorbed well enough to change blood and urine markers (Harris et al., 2013). Detailed human pharmacokinetics, such as half-life and tissue distribution, are not well established in published trials. Taking it with a meal is a reasonable default.

In the Harris study, PQQ changed plasma inflammatory markers and urinary metabolites, which shows it is absorbed in meaningful amounts (Harris et al., 2013).

Unlike curcumin, which is notoriously poorly absorbed, PQQ does not appear to need special formulations to have measurable effects in people (Harris et al., 2013).

The cognitive effects in aged mice (Yan et al., 2026) suggest PQQ or its downstream signals reach the brain, but tissue levels in humans have not been measured.

Take PQQ with a meal. No trial has compared fed and fasting dosing, but a meal is a sensible default, and morning or midday dosing avoids any energizing effect at bedtime.

Drug interactions with PQQ are not well-characterized in clinical literature. Given its antioxidant properties, there is a theoretical concern that PQQ could interfere with chemotherapy drugs or radiation therapy that rely on oxidative mechanisms to kill cancer cells, though this has not been studied clinically. Cancer patients undergoing active treatment should consult their oncologist before starting PQQ supplementation.

What does PQQ do for the body?

In cell studies, PQQ stimulates mitochondrial biogenesis through CREB and PGC-1α (Chowanadisai et al., 2010). In people, 12-week trials found better attention, memory and cognitive flexibility (Itoh et al., 2016) (Shiojima et al., 2022), and a small study found lower CRP and IL-6 (Harris et al., 2013).

Is PQQ worth taking?

For adults over 40 interested in cognitive support, PQQ at 20 mg/day has reasonable early evidence: two 12-week RCTs found cognitive benefits (Itoh et al., 2016) (Shiojima et al., 2022), and tolerance has been good. Expect modest, gradual changes rather than an acute effect.

How long does PQQ take to work?

The positive trials measured outcomes after 12 weeks (Itoh et al., 2016) (Shiojima et al., 2022), and a 2024 review notes that some measures improved by 8 weeks in younger adults (Ikemoto et al., 2024). Give it at least two to three months.

Can you take PQQ and CoQ10 together?

Yes. They act on different parts of mitochondrial function, and Japanese studies summarized in a 2024 review suggest CoQ10 enhances PQQ's cognitive effects (Ikemoto et al., 2024). In rats, though, the combination did no better than PQQ alone (Ohwada et al., 2008), so treat synergy as possible rather than proven.