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PQQ (pyrroloquinoline quinone) and blood triglycerides: grade C

Limited evidence. Direction: No effect.

C LimitedShort-term only

Educational guidance, not medical advice

Why this grade

Rubric condition met: One small supplier-run RCT null on triglycerides, plus an uncontrolled crossover study; not adequate for N, so C with direction none

In a 12-week randomized, placebo-controlled trial of 29 healthy Japanese adults aged 40 to 57 with normal to moderately high triglycerides, 20 mg/day of BioPQQ did not change mean serum triglycerides; the first author was employed by Mitsubishi Gas Chemical. In an uncontrolled crossover study of 10 adults, standard clinical indices including triglycerides were not altered. Evidence is too small for N, so the grade is C with direction none.

How we grade evidence

Studies this grade rests on

EffectMixedNo effectSize shows participants (n)201020152020RCTCrossover RCTNakano 2015, 2015: RCT, n = 29, result not recordedHarris 2013, 2013: crossover RCT, n = 10, result not recorded
each study this grade rests on, by publication year and design. Solid: effect versus the comparator; half-filled: mixed; hollow: no effect; dashed: result not recorded yet. Larger marks had more participants.
Show the numbers
StudyYearDesignParticipantsResult
Harris 20132013crossover RCT10result not recorded
Nakano 20152015RCT29result not recorded

Dietary pyrroloquinoline quinone (PQQ) alters indicators of inflammation and mitochondrial-related metabolism in human subjects.

Harris CB, Chowanadisai W, Mishchuk DO. Dietary pyrroloquinoline quinone (PQQ) alters indicators of inflammation and mitochondrial-related metabolism in human subjects J Nutr Biochem, 2013. PMID 24231099

Result not recorded
Design
Crossover study without placebo, single dose and 76-hour daily dosing
Sample
n = 10
Population
Healthy adults (5 women, 5 men)
Funding
Funding: not stated in the PubMed or Crossref record; full text not read.

Effects of Pyrroloquinoline Quinone Disodium Salt Intake on the Serum Cholesterol Levels of Healthy Japanese Adults.

Nakano M, Kawasaki Y, Suzuki N. Effects of Pyrroloquinoline Quinone Disodium Salt Intake on the Serum Cholesterol Levels of Healthy Japanese Adults J Nutr Sci Vitaminol (Tokyo), 2015. PMID 26226960

Result not recorded
Design
Randomized, placebo-controlled, double-blind trial, 12 weeks
Sample
n = 29
Population
Healthy Japanese adults aged 40 to 57 with normal to moderately high triglycerides
Funding
Not stated in PubMed or Crossref; first author employed by Mitsubishi Gas Chemical Company, Inc.

Search and history

Search (): pyrroloquinoline[tiab] AND (lipid*[tiab] OR cholesterol[tiab] OR triglyceride*[tiab]) AND humans[mh]

  • Graded C (proposed): Proposed in the monograph draft
  • C to C (approved): Editor sign-off November 13, 2026: grade matches the editor-approved final page