PQQ (pyrroloquinoline quinone) and brain
What 3 graded rows on pqq (pyrroloquinoline quinone) agree on for brain, and where they differ. Counted side by side, never averaged.
Consensus finder Rows from the PQQ (pyrroloquinoline quinone) page, reviewed Oct 21, 2026 How it decides
What the rows agree on
Each block and row is one graded row from the PQQ (pyrroloquinoline quinone) page, with its PubMed record.
Your question
PQQ (pyrroloquinoline quinone) and brain
3 rows · 140 peopleThey agree: all 3 rows found an improvement.
- CGrade C× 2
- DGrade D× 1
- Rows
- 3
- Trials
- 3
- People
- 140
What the rows share
From the rowsThe best-graded row, grade C, is a randomized trial of 62 people (2023) and found an improvement.
The rows run from 20 to 62 people, published from 2016 to 2023: 3 single studies.
The rows
3 improved- CGrade CComposite and verbal memory in adults aged 20–65 · Improved
RCT · n 62 · 2023 · Healthy Japanese adults aged 20–65 (62 analysed of 70 enrolled)
20 mg/day · 12 weeks
Composite memory and verbal memory improved vs placebo at 12 weeks; in an age-split analysis, cognitive flexibility, processing speed and executive speed improved at 8 weeks in those aged 20–40. No adverse events.
Row on the PQQ (pyrroloquinoline quinone) page · PubMed 36807425 (opens PubMed)
- CGrade CMemory, attention and cognitive flexibility · Improved
RCT · n 58 · 2022 · Japanese adults (mean age about 71) who felt more forgetful (58 of 64 completed)
21.5 mg/day · 12 weeks
Composite memory, verbal memory, reaction time, complex attention, cognitive flexibility, executive function and motor speed improved vs placebo; no adverse events.
Row on the PQQ (pyrroloquinoline quinone) page · PubMed 34415830 (opens PubMed)
- DGrade DPrefrontal blood flow and oxygenation · Improved
RCT · n 20 · 2016 · Healthy adults aged 50–70
20 mg/day · 12 weeks
Baseline haemoglobin and total haemoglobin in the right prefrontal cortex rose significantly after PQQ.
Row on the PQQ (pyrroloquinoline quinone) page · PubMed 27526146 (opens PubMed)