VCVITAMINS/CHART

The Bottom Line

Yes, you can take PQQ and milk thistle together safely, as they do not interact.

VERDICT

PQQ and Milk Thistle together are neutral: you can combine them without worrying about adverse interactions. PQQ supports cellular energy, while milk thistle (silymarin) supports liver function. These two supplements work through separate pathways, making them a safe pairing.

Safe to combine Limited evidence
01 / MECHANISM

How They Interact

PQQ (pyrroloquinoline quinone) is a water-soluble redox cofactor that promotes mitochondrial biogenesis and acts as an antioxidant. Milk thistle's active component, silymarin, is a fat-soluble complex of flavonolignans that is poorly absorbed orally and works mainly in the liver through antioxidant and anti-inflammatory pathways. The two molecules do not share a common transporter or receptor system, and their mechanisms of action are independent. While silymarin can inhibit certain cytochrome P450 enzymes (CYP3A4, CYP2C9), PQQ is not primarily metabolized by these enzymes, so a relevant pharmacokinetic interaction is unlikely. In short, there is no known biological reason for PQQ and silymarin to significantly amplify or block each other's effects.

02 / BEST PRACTICES

How To Take Them

If you are already taking PQQ and want to add milk thistle, the simplest approach is to take both at breakfast. Milk thistle absorbs better when taken with food, especially food containing healthy fats like eggs, avocado, or olive oil. PQQ can also be taken with food; empty stomach is fine, but breakfast helps avoid any mild stomach upset. You can take them in the same sitting — no spacing is required. If you miss a dose, skip it and resume at your next meal; do not double. For best absorption from milk thistle, choose a phytosome or enhanced-absorption form. For PQQ, a disodium salt form is fine, but standard PQQ is also well absorbed.

03 / FORM MATTERS

Form & Quality Differences

PQQ is relatively well absorbed in its free form, but some forms such as the disodium salt are more soluble, which can slightly improve bioavailability. For milk thistle, the standard silymarin extract is poorly absorbed, but phytosome forms (silymarin complexed with phosphatidylcholine) are significantly better absorbed. If you want the strongest effect from milk thistle, look for a phytosome or enhanced-absorption formulation.

04 / COMMON STACKS

Where This Pair Shows Up

This pair occasionally appears in comprehensive liver- and energy-support formulas alongside CoQ10 and alpha-lipoic acid. It is also seen in some anti-aging mitochondrial health stacks, where PQQ is paired with CoQ10 and nicotinamide riboside, and milk thistle is added for liver support.

Multivitamins Prenatals Performance Longevity
05

Practical Tips

06

Frequently Asked Questions

Who Should Be Careful There are no specific warnings for combining PQQ and milk thistle, but certain people should be cautious with these supplements individually. If you are pregnant or breastfeeding, avoid using these supplements because safety data are limited. Milk thistle may interact with medications metabolized by the liver, including certain statins, anticoagulants, and diabetes medications, so talk to your doctor if you take any prescription drugs. PQQ has not been studied in people with kidney or liver disease, so discuss supplementation with your healthcare provider if you have a chronic condition.
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Sources & Further Reading

  1. NIH ODS NIH Office of Dietary Supplements — PQQ Fact Sheet
  2. NIH ODS NIH Office of Dietary Supplements — Milk Thistle Fact Sheet
  3. Examine.com Examine.com — PQQ interaction page
  4. Examine.com Examine.com — Milk Thistle interaction page

Reviewed by Caroline M. on January 15, 2025 for accuracy against the sources listed above. This page is educational and is not a substitute for professional medical advice.

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The matrix has 86 supplements and 7310 pairwise interactions. Click any cell to see the full breakdown.

Back To The Vitamins Chart All Milk Thistle (Silymarin) Interactions All PQQ (Pyrroloquinoline Quinone) (cellular health) Interactions