NutriStack
PQQ and Vitamin C, a synergy.
Vitamin C and PQQ can work together as a coupled redox antioxidant system. Ascorbic acid donates electrons to convert PQQ into PQQH2, the form responsible for PQQ's potent radical-scavenging and singlet-oxygen quenching activity. The two compounds naturally coexist in plant foods and human tissues, and laboratory studies at physiological pH (7.4) demonstrate this reduction-and-regeneration cycle directly. This is a favorable, additive antioxidant pairing rather than a risk.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
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What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Pair type
- Synergy
- Evidence (highest tier)
- Moderate
- Source citations
- 3 sources
- Stack Score effect
- +2 to your Stack Score (per scored synergy row).
- Scope
- Supplement × Supplement
- Last verified
- May 30, 2026
Synergy · Moderate evidence
Synergy
What is happening. Vitamin C and PQQ can work together as a coupled redox antioxidant system. Ascorbic acid donates electrons to convert PQQ into PQQH2, the form responsible for PQQ's potent radical-scavenging and singlet-oxygen quenching activity. The two compounds naturally coexist in plant foods and human tissues, and laboratory studies at physiological pH (7.4) demonstrate this reduction-and-regeneration cycle directly. This is a favorable, additive antioxidant pairing rather than a risk.
Mechanism. PQQ is a redox-cycling o-quinone whose strongest free-radical scavenging activity resides in its reduced quinol form, PQQH2. Vitamin C (ascorbic acid) directly reduces PQQ to PQQH2 in roughly a 2:1 ascorbate-to-PQQ stoichiometry (one PQQ reduced by two ascorbate molecules), and the PQQH2 generated can be re-oxidized back to PQQ by air oxidation, allowing the pair to operate as a coupled, regenerating antioxidant cycle. In effect, vitamin C helps keep PQQ in (or convert it to) its antioxidant-active reduced state, while PQQ provides catalytic redox cycling that is efficient on a molar basis.
Recommendation. No separation needed; these are complementary. Taking PQQ (typically 10 to 20 mg per day) alongside vitamin C (commonly 250 to 1000 mg per day) is reasonable and may help maintain PQQ in its antioxidant-active reduced form. Both are well tolerated together. Take with food to improve comfort. No dose change is required for either.
Minimum separation. None; can be taken together
Sources (3)
- Akagawa M et al. Pyrroloquinoline quinone (PQQ) is reduced to pyrroloquinoline quinol (PQQH2) by vitamin C, and PQQH2 produced is recycled to PQQ by air oxidation in buffer solution at pH 7.4. Bioscience, Biotechnology, and Biochemistry, 2016.
- Pyrroloquinoline Quinone overview, ScienceDirect Topics (Agricultural and Biological Sciences): redox cycling, PQQH2 as the antioxidant-active form, and coexistence of PQQ and ascorbate in tissues.
- Antioxidant pharmacology reviews describing PQQ redox cycling and free-radical scavenging activity.
Stack Score
How this pair moves the number.
Effect on the composite score
If both PQQ and Vitamin C are in the same stack, this pair applies +2 to your Stack Score (per scored synergy row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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