What kind of interaction is it?

Caution: an interaction that may reduce efficacy or raise side-effect risk and warrants monitoring.

Is this interaction backed by published research?

Yes. NutriStack lists 1 citation row for the Milk Thistle + Pterostilbene pair, each linking to PubMed by PMID where available. Full sourcing methodology at https://nutristackapp.com/methodology/interactions.

Supplement × Supplement·a caution·Insufficient evidence

Milk Thistle + Pterostilbene

Q: Can I take Milk Thistle and Pterostilbene together?

Possibly, but with caution. Milk Thistle and Pterostilbene have a documented caution-tier interaction. Both pterostilbene and silymarin from milk thistle are metabolized by hepatic conjugation enzymes (glucuronidation and sulfation), and silymarin can inhibit these pathways. Combined use may alter the clearance of pterostilbene or shared substrates.

Q: How does this affect a NutriStack Stack Score?

-5 to your Stack Score per scored caution row.

Caution Insufficient evidence

Both pterostilbene and silymarin from milk thistle are metabolized by hepatic conjugation enzymes (glucuronidation and sulfation), and silymarin can inhibit these pathways. Combined use may alter the clearance of pterostilbene or shared substrates.

Supplement × Supplement

Open the interaction checker → Read the methodology

From the database

What the row says.

Every entry follows the same shape: what is happening, the mechanism, and the recommendation.

Substances

Milk Thistle and Pterostilbene

Pair type

Caution

Evidence

Insufficient

Source citations

Scope

Supplement × Supplement

Last verified

June 4, 2026

CautionInsufficient evidence

What is happening. Both pterostilbene and silymarin from milk thistle are metabolized by hepatic conjugation enzymes (glucuronidation and sulfation), and silymarin can inhibit these pathways. Combined use may alter the clearance of pterostilbene or shared substrates.

Mechanism. Silymarin components inhibit UDP-glucuronosyltransferases and certain CYP enzymes involved in phase I and phase II metabolism, which overlaps with pterostilbene's conjugative clearance pathways.

Recommendation. Use the combination cautiously, especially in people with liver conditions or on hepatically cleared medications. Keep doses moderate and monitor for unexpected effects.

Stack Score

How it moves the number.

Effect on the composite score

If both Milk Thistle and Pterostilbene are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).

The full algorithm, the clamping rules, and four worked stacks are at /methodology/stack-score.

Sources

Sources, by evidence tier.

Every claim on this page is cited. PMIDs link straight to PubMed.

Reference material

1Brantley SJ, et al. Two flavonolignans from milk thistle inhibit CYP2C9-mediated metabolism. Drug Metab Dispos. 2010.Needs sourceNo link

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