PQQ (pyrroloquinoline quinone)

What it is

Pyrroloquinoline quinone (PQQ) is a compound found in tiny amounts in foods such as soy, green vegetables, fermented foods and human milk. It is not currently recognised as an essential nutrient.

Supplements are marketed for supporting mitochondria, energy and cognitive function, often alongside CoQ10.

Most of the exciting findings come from cell and animal studies; the human research is limited to small trials.

How it works

In lab studies, PQQ appears to act as a redox cofactor and to influence signalling pathways linked to the creation of new mitochondria. It also has antioxidant activity. How much of this applies in people at supplement doses is not established.

What the evidence says

• Limited Mitochondrial or energy markers
  Mostly lab and animal research, with a few small human studies.
• Limited Memory and attention
  A few small trials, some combined with CoQ10, suggest slight improvements in older adults; findings need replication.
• Weak Sleep quality and fatigue
  Small studies hint at benefits but are not strong enough to rely on.
• Weak Lowering inflammation markers
  Small studies show some changes in markers, with unclear real-world meaning.

Evidence ratings are our plain-English summary of how much good human research exists, not a promise of results. How we rate evidence.

Dosage and timing

• Typical doses in studies and products are 10-20 mg daily.
• Doses in human trials have run for a few weeks to a few months.
• There is no official recommended intake; check current guidance and the label.
• Higher doses are not proven to work better.

Forms and what to look for

• PQQ disodium salt is the common supplement form and the one used in most human studies.
• Often sold combined with CoQ10 as a mitochondrial stack; the combined benefit is not well proven.
• Check the label states mg of PQQ per capsule rather than a total blend weight.
• Avoid unlabelled powders from unknown sellers.

What to expect, and when

• Studies assessed effects over weeks to a few months.
• Most people will not notice a clear difference.
• Judge any change cautiously given placebo effects.

Side effects

• Generally well tolerated at typical doses in short studies.
• Headache or dizziness in some people.
• Mild stomach upset or nausea.
• Insomnia or feeling wired if taken late in the day.

Interactions

• No well-established drug interactions, but little research exists.
• Antioxidant supplements: combining several is not proven helpful.
• Chemotherapy: check with your oncology team before using antioxidants.
• Kidney conditions: unusually high doses in animals have affected kidneys; speak to a clinician.

Who should avoid it

• Pregnant or breastfeeding women, due to lack of data.
• People with kidney disease, unless a clinician agrees.
• Children and teenagers.
• People on regular medication should check with a pharmacist.

Risks and safety

• Long-term human safety data are limited.
• Quality varies between brands because the market is small.
• Product availability and regulatory status in the UK and EU can change; check current guidance.
• Not a recognised vitamin, despite sometimes being marketed as one.

Buying well: quality and testing

• Choose brands with third-party testing and a certificate of analysis.
• Look for PQQ amount per capsule that matches studied doses.
• Be sceptical of claims that PQQ "builds new mitochondria" in people.
• Prefer simple products without large proprietary blends.

Bottom line

PQQ is an interesting but early-stage supplement. Human evidence is small and mostly short-term, so treat any benefit as unproven. It may suit curious adults who understand it is an experiment; it is not a substitute for sleep, exercise and a decent diet.