NutriStack
CautionModerate evidence
What is happening. Melatonin can add to primidone and phenobarbital-metabolite sedation.
Mechanism. Additive CNS depressant effects.
Recommendation. Use cautiously and avoid driving if impaired.
Supplement × Prescription·a caution·Moderate evidence
Melatonin + Primidone
Caution
Moderate evidence
Melatonin can add to primidone and phenobarbital-metabolite sedation.
From the database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, and the recommendation.
Pair type
Caution
Evidence
Moderate
Source citations
1
Scope
Supplement × Prescription
Last verified
June 4, 2026
Stack Score
How it moves the number.
Effect on the composite score
If both Melatonin and Primidone 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
1- 1U.S. National Library of Medicine. Primidone tablets US Prescribing Information. 2025.Needs sourceNo link
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