PQQ for Fatigue / cognition

Evidence grade D — Weak, small studies

Assembled by the app from other entries in this library. It adds no evidence of its own — follow the links to the entries it draws on.

1 at grade D — 1 graded row

What is known

Each outcome with its grade (how strong the evidence is, A to D), the size of the effect where the entry records one, and how often studies agree.

Outcome	Grade	Effect size	Agreement
Fatigue / cognitionWeak, small studies	Evidence grade D	Trivial	low

Read off the same rows as above. Nothing here is added that the entry does not itself record.

For fatigue / cognition, PQQ earns evidence grade D (trivial effect, low consistency) — the evidence does not support the claim. Weak, small studies

Proposed to stimulate the growth of new mitochondria and act as an antioxidant.

10–20 mg/day if trialing.

Appears safe at these doses.

Thin evidence for a lot of marketing. Not a priority.

As the entry records it, from the studies it summarises. Not a recommendation for you — doses that suit a trial population may not suit you.

Entries that share this one's tags or conditions.

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NMN for Physical function / insulin sensitivityEvidence grade C — Early, smallEvidence grade C

This entry lists no references of its own — it is assembled from the entries it links to, whose sources are on their pages.

Last revised Jul 10, 2026. A grade is this entry's reading of the evidence, not medical advice.