【Brain Health Ingredient Series 2】 Pyrroloquinoline Quinone (PQQ): The "Energy Activator" Protecting Neuronal Cells

1. What is Pyrroloquinoline Quinone (PQQ)?

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PQQ was discovered in the late 1960s. It is a non-vitamin, water-soluble redox coenzyme (methanol dehydrogenase) [8] — the third cofactor identified in membrane-bound bacterial dehydrogenases, following flavin nucleotides and nicotinamide nucleotides [12,17]. PQQ is widely present in soil, breast milk, and common foods such as spinach and broccoli, and trace amounts can also be synthesized in the human body [13]. Although it is not a vitamin, due to its coenzyme-like essential role, it is often referred to as the “14th vitamin” and is recognized as a “next-generation key ingredient for brain health.”

 

2. Basic Characteristics

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PQQ itself has poor water solubility and is chemically active, making it prone to reduction and degradation. However, its sodium salt form (PQQ disodium salt) exhibits significantly improved water solubility, stability, and bioavailability. PQQ disodium salt is a reddish-brown aromatic orthoquinone compound that dissolves easily in water [15], is thermally stable, and emits a distinctive green fluorescence. Under weakly acidic to neutral conditions, it dissociates into anions and can form adducts with water, alcohols, and amines. PQQ can be produced through chemical synthesis and microbial fermentation methods.

 

3. Functional Effects: From Neuroprotection to Cognitive Enhancement

Unlike single-function ingredients, PQQ exerts multi-dimensional protection over brain health.

(1) Regulating Neurotrophic Factors and Promoting Neurogenesis

Image source: 《The effects of pyrroloquinoline quinone disodium salt on brain function and physiological processes》

 

Neurotrophic factors (such as BDNF and NGF) are essential nutrients for the brain[9]. PQQ is one of the few known compounds capable of activating BDNF, stimulating the hippocampus to generate new, mature neurons [10,11]. By increasing the “hardware” of the brain, PQQ strengthens the physiological foundation of memory and cognition[4].

(2) Boosts Mitochondrial Energy and Cellular Vitality

Image source:《Pyrroloquinoline-quinone to reduce fat accumulation and ameliorate obesity progression》

 

Mitochondrial dysfunction leads to insufficient ATP and excessive free radical release, accelerating cell death [2]. PQQ activates key pathways such as PGC-1α to promote mitochondrial biogenesis and energy metabolism [20], thereby protecting nerve cells and alleviating brain fatigue [7].

(3) Inhibiting Oxidation and Inflammation to Protect Nerve Cells

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PQQ can directly scavenge free radicals and interrupt oxidative stress, reducing damage to neuronal membranes [3]. It also inhibits the release of inflammatory cytokines such as TNF-α and IL-6 [16,20], effectively building a protective barrier for the brain and lowering the risk of neurodegeneration.

 

4. Regulatory Status: A Globally Recognized Safe Ingredient

● Canada: In 2012, Health Canada (HC) approved PQQ as a natural health product.

● Japan: In 2013, the Ministry of Health, Labour and Welfare (MHLW) of Japan approved PQQ as a non-pharmaceutical ingredient and included it in the “List of Functional Food Ingredients,” allowing claims that it “supports brain health.”

● United States: In 2016, the U.S. Food and Drug Administration (FDA) granted PQQ GRAS (Generally Recognized As Safe) status, permitting its use in foods and dietary supplements without setting a maximum daily intake limit.

● European Union: In 2018, the European Food Safety Authority (EFSA) approved PQQ as a novel food ingredient for use in dietary supplements for adults (excluding pregnant and breastfeeding women) at a limit of 20 mg/day.

● China: In March 2022, the National Health Commission (NHC) approved chemically synthesized PQQ as a new food ingredient [21] for use in populations other than infants, pregnant, or breastfeeding women, with a daily intake limit of ≤20 mg. It may also be used in beverages. In October 2023, the NHC approved fermented PQQ as a new food ingredient. Currently, PQQ is only approved in solid or beverage forms (not capsules or tablets).

 

5. Clinical Evidence: Proven Benefits for Brain Health and Function

●A study published in 《NPJ Aging》 confirmed that PQQ can restore mitochondrial morphological damage caused by hydrogen peroxide exposure, improving mitochondrial dynamics and thereby delaying cellular aging[1,6].

● A randomized controlled trial published in 《Food & Function》 showed that daily supplementation with 20 mg of PQQ for 12 weeks significantly enhanced composite and verbal memory in all participants, particularly among older adults; even after 8 weeks, younger participants demonstrated improved cognitive flexibility, processing speed, and executive performance [14].

● A Japanese study involving healthy adults aged 40–80 found that daily supplementation with 21.5 mg of PQQ disodium salt for 12 weeks significantly improved composite memory and reaction time scores across seven cognitive function tests compared with the placebo group, with improvements observable as early as week six[18].

 

6. Safety Profile: Demonstrated Long-Term Tolerability and Safety

Numerous clinical studies and practical applications indicate that PQQ is highly safe.

● Mutagenicity and Genotoxicity: PQQ has shown no genetic or cytotoxic effects at doses up to 5000 μg and does not induce mutations dependent on metabolic activation systems, meeting genetic toxicology safety standards[19].

● Acute Toxicity: Studies in rats and mice have shown that the median lethal dose (LD₅₀) of PQQ exceeds 5000 mg/kg body weight. According to the Globally Harmonized System (GHS), PQQ is not classified under acute toxicity categories, indicating very low risk even at high single doses[22].

● Subchronic Toxicity: No evidence currently suggests that PQQ exhibits subchronic toxicity.

● Teratogenicity: No teratogenic effects have been observed in animal models.

 

7. Recommended Intake and Dosage

● For Daily Health Maintenance (Healthy Adults): 10–20 mg per day, taken once or divided into two doses.

● For Targeted Cognitive Enhancement (Mental Workers, Middle-aged, and Elderly): 20 mg per day, preferably combined with 300–600 mg Coenzyme Q10 (to synergistically enhance mitochondrial function) or 100 mg Phosphatidylserine (for stronger neuroprotective effects).

 

8. Precautions

● Not recommended for infants or children under 14 years old (due to limited safety data). Pregnant or breastfeeding women should use under the guidance of a physician or nutritionist.

● While no specific drug interactions have been reported, individuals taking anticoagulants, antidiabetic drugs, or those with severe liver or kidney conditions should consult healthcare professionals before supplementation.

● Product purity matters — high-quality PQQ should have a purity ≥99% to ensure efficacy and minimize digestive burden.

● Some individuals may experience mild insomnia initially (due to increased brain activity); it is recommended to take PQQ after breakfast or lunch, and avoid nighttime intake.

● Not a substitute for medication: individuals with significant cognitive impairment (e.g., severe memory loss or delayed reactions affecting daily life) should seek medical evaluation rather than relying solely on supplements.

 

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