NutriDex

The Supplement Research Compendium
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PQQ

Pyrroloquinoline Quinone

Redox cofactor marketed for mitochondria, memory and energy.

Preliminary evidence ⏳Longevity🧠Nootropic

✚ Updated · How we grade evidence

Evidence tier
Preliminary
Research weight
Citations
7 verified / 7
Classification
Longevity
❝
What the evidence says. Graded preliminary: a handful of small (n≈30–65), mostly short and largely industry-funded RCTs from a few Japanese groups report modest gains in memory, attention, lipids and sleep, but there is no independent meta-analysis, effect sizes are small, and most human mitochondrial claims rest on animal data. (Preliminary evidence: Early or small human trials; promising but not yet conclusive.)

What is PQQ?

PQQ (Pyrroloquinoline Quinone) is a longevity supplement used for memory & attention in older adults. NutriDex grades the human evidence as Preliminary. PQQ is a quinone redox cofactor found in trace amounts in foods like fermented soy, kiwi and human milk. It is sold as a 'mitochondrial' nootropic and anti-aging aid. The human evidence is thin: small randomized trials (typically 20 mg/day of the disodium salt for 8–12 weeks) report modest improvements in composite and verbal memory and in selective attention, mainly in middle-aged and older adults, plus reduced LDL cholesterol in people with high baseline levels (roughly 156→132 mg/dL) and better self-reported sleep and fatigue. A 2024 RCT in mild cognitive impairment found higher serum BDNF and improved orientation but no broad cognitive benefit. Most trials are small, brief and funded by manufacturers of branded PQQ, with no independent meta-analysis, so the size and durability of any real benefit remain uncertain.

Purported Benefits

✓Memory & attention in older adults
✓Mitochondrial support
✓Lower LDL cholesterol
✓Reduced fatigue & better sleep

Evidence by outcome

The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.

OutcomeEvidenceEffectStudies
Memory & attention in older adultsSmall manufacturer-funded RCTs show modest gains; a 2024 MCI trial found no broad cognitive benefit. Preliminary ↑ benefit · small 3
Lower LDL cholesterolOne RCT lowered LDL (~156→132) only in people with high baseline LDL; n=29, unreplicated. Preliminary ↑ benefit · moderate 1
Improve mood, sleep & fatigueImprovements came from an open-label 8-wk study with no placebo control. Preliminary ↑ benefit 1

Dosing & Compounds

Typical Dose
20 mg/day of PQQ disodium salt is the dose used in most human trials; products supply 10–20 mg, sometimes paired with CoQ10.
Active Compounds
Pyrroloquinoline quinone (free acid)PQQ disodium salt (BioPQQ)

Safety & Cautions

PQQ appears well tolerated in short human trials, with no serious adverse events at 20 mg/day; mild GI upset, headache and sleep changes are reported anecdotally. Long-term safety is unstudied, and animal data hinted at reversible kidney changes at very high doses. Because trials suggest LDL-lowering and possible blood-glucose effects, use caution if you take lipid- or glucose-lowering drugs, and tell your clinician. Safety in pregnancy, breastfeeding and children is not established; avoid in those groups. Educational only — always check with your doctor or pharmacist before combining PQQ with any medicine.

Key Studies

RCT Tamakoshi 2023 ✓ Full text
20 mg/day for 12 wk (n=62) significantly improved composite and verbal memory; gains in older adults at 12 wk.
RCT Baltic 2024 ✓ PubMed
6-wk dihydro-PQQ in 34 elderly with MCI raised serum BDNF (P=0.01) and ADAS-Cog orientation (P=0.03), but not global cognition.
RCT Itoh 2016 ✓ PubMed
20 mg/day BioPQQ for 12 wk in 41 healthy elderly improved selective attention (Stroop) and working memory vs placebo.
RCT Nakano 2015 ✓ Full text
20 mg/day for 12 wk lowered LDL-cholesterol in adults with baseline LDL >=140 mg/dL (~156 to 132 mg/dL); triglycerides unchanged (n=29).
RCT Harris 2013 ✓ PubMed
Single/short PQQ dosing in 10 adults lowered plasma CRP and IL-6 and shifted urinary metabolites toward enhanced mitochondrial function.
RCT Nakano 2012 ✓ Full text
Open-label 20 mg/day for 8 wk (n=17) improved all POMS mood subscales and several sleep-quality measures; no placebo control.
Review Akagawa 2024 (review) ✓ PubMed
Narrative review concludes human PQQ data remain limited and short-term; calls for dose-response trials; reports no toxicity signals.
7 sources cited · 7 verified Search all studies on PubMed ↗

Common questions about PQQ

What is PQQ used for?

PQQ is most often taken for Memory & attention in older adults, Mitochondrial support, Lower LDL cholesterol, Reduced fatigue & better sleep. Redox cofactor marketed for mitochondria, memory and energy.

Does PQQ work — what does the evidence say?

Preliminary evidence. Early or small human trials; promising but not yet conclusive. PQQ is a quinone redox cofactor found in trace amounts in foods like fermented soy, kiwi and human milk. It is sold as a 'mitochondrial' nootropic and anti-aging aid. The human evidence is thin: small randomized trials (typically 20 mg/day of the disodium salt for 8–12 weeks) report modest improvements in composite and verbal memory and in selective attention, mainly in middle-aged and older adults, plus reduced LDL cholesterol in people with high baseline levels (roughly 156→132 mg/dL) and better self-reported sleep and fatigue. A 2024 RCT in mild cognitive impairment found higher serum BDNF and improved orientation but no broad cognitive benefit. Most trials are small, brief and funded by manufacturers of branded PQQ, with no independent meta-analysis, so the size and durability of any real benefit remain uncertain.

What is the typical dose of PQQ?

20 mg/day of PQQ disodium salt is the dose used in most human trials; products supply 10–20 mg, sometimes paired with CoQ10.

Is PQQ safe? Any cautions or side effects?

PQQ appears well tolerated in short human trials, with no serious adverse events at 20 mg/day; mild GI upset, headache and sleep changes are reported anecdotally. Long-term safety is unstudied, and animal data hinted at reversible kidney changes at very high doses. Because trials suggest LDL-lowering and possible blood-glucose effects, use caution if you take lipid- or glucose-lowering drugs, and tell your clinician. Safety in pregnancy, breastfeeding and children is not established; avoid in those groups.

How many studies support PQQ?

NutriDex cites 7 sources for PQQ, graded "Preliminary".

Cite this page
APA

Peh, D. (2026). PQQ (Pyrroloquinoline Quinone): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 26 Jun 2026, from https://nutridex.info/s/pqq

BibTeX
@misc{nutridex_pqq,
  author       = {Peh, Daryl},
  title        = {PQQ (Pyrroloquinoline Quinone): Benefits, Dosage, Side Effects \& Evidence},
  year         = {2026},
  howpublished = {NutriDex --- The Supplement Research Compendium},
  url          = {https://nutridex.info/s/pqq},
  note         = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-06-26}
}

For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.

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