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 2 citation rows for the Valganciclovir + Zinc pair, each linking to PubMed by PMID where available. Full sourcing methodology at https://nutristackapp.com/methodology/interactions.

Supplement × Prescription·a caution·Moderate evidence

Valganciclovir + Zinc

Q: Can I take Valganciclovir and Zinc together?

Possibly, but with caution. Valganciclovir and Zinc have a documented caution-tier interaction. Valganciclovir frequently causes neutropenia and other cytopenias. High-dose or prolonged zinc supplementation can induce copper deficiency, which itself produces neutropenia and anemia. Combining chronic high-dose zinc with a known myelosuppressive antiviral can compound the risk of low neutrophil counts and complicate interpretation of the blood-count abnormalities that already require monitoring during therapy.

Q: How does this affect a NutriStack Stack Score?

-5 to your Stack Score per scored caution row.

Caution Moderate evidence

Valganciclovir frequently causes neutropenia and other cytopenias. High-dose or prolonged zinc supplementation can induce copper deficiency, which itself produces neutropenia and anemia. Combining chronic high-dose zinc with a known myelosuppressive antiviral can compound the risk of low neutrophil counts and complicate interpretation of the blood-count abnormalities that already require monitoring during therapy.

Supplement × Prescription

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

Valganciclovir and Zinc

Pair type

Caution

Evidence

Moderate

Source citations

Scope

Supplement × Prescription

Last verified

June 4, 2026

CautionModerate evidence

What is happening. Valganciclovir frequently causes neutropenia and other cytopenias. High-dose or prolonged zinc supplementation can induce copper deficiency, which itself produces neutropenia and anemia. Combining chronic high-dose zinc with a known myelosuppressive antiviral can compound the risk of low neutrophil counts and complicate interpretation of the blood-count abnormalities that already require monitoring during therapy.

Mechanism. Excess zinc upregulates intestinal metallothionein, which binds dietary copper and increases its fecal loss, producing copper deficiency. Copper-deficiency myelopathy causes neutropenia and anemia that are additive to ganciclovir's direct marrow suppression.

Recommendation. Avoid chronic high-dose zinc (generally above roughly 40 mg/day of elemental zinc) while on valganciclovir unless directed by a clinician. Keep any zinc intake within recommended daily amounts, and report new or worsening cytopenias so the cause can be sorted out.

Stack Score

How it moves the number.

Effect on the composite score

If both Valganciclovir and Zinc 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

1Willis MS, et al. Zinc-induced copper deficiency: a report of three cases and review of the literature. American Journal of Clinical Pathology. 2005.Needs sourceNo link
2Valganciclovir (Valcyte) US Prescribing Information. Genentech. 2022.Needs sourceNo link

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