NutriStack
Citalopram and Melatonin, a caution.
Severe sedation has been reported after melatonin was added to a regimen that included citalopram, with the authors judging a melatonin-citalopram pharmacokinetic interaction as the most likely explanation. The case also involved other sedating medicines, so the risk is most important when melatonin is stacked with citalopram plus opioids, tricyclic antidepressants, sleep medicines, alcohol, or other CNS depressants. Watch for unusual next-day grogginess, confusion, slowed breathing, or impaired coordination.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Citalopram and Melatonin
- Pair type
- Caution
- Evidence (highest tier)
- Moderate
- Source citations
- 2 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Caution · Moderate evidence
Caution
What is happening. Severe sedation has been reported after melatonin was added to a regimen that included citalopram, with the authors judging a melatonin-citalopram pharmacokinetic interaction as the most likely explanation. The case also involved other sedating medicines, so the risk is most important when melatonin is stacked with citalopram plus opioids, tricyclic antidepressants, sleep medicines, alcohol, or other CNS depressants. Watch for unusual next-day grogginess, confusion, slowed breathing, or impaired coordination.
Mechanism. The published case suggested product-dependent CYP inhibition by melatonin products, including CYP1A2, CYP2C19, and CYP3A7, with possible effects on citalopram exposure. Citalopram is clinically sensitive to pharmacokinetic interactions involving CYP pathways, and melatonin can also add pharmacodynamic sleep-promoting effects.
Recommendation. Use the lowest effective melatonin dose if you take citalopram, and avoid adding melatonin when other sedating medicines are already in the stack unless your prescriber approves it. Do not drive or use machinery after starting or increasing melatonin until you know how the combination affects you. Seek urgent care for extreme sleepiness, confusion, fainting, or slow breathing.
Sources (2)
- Foster BC, Cvijovic K, Boon HS, Tam TW, Liu R, Murty M, Vu D, Jaeger W, Tsuyuki RT, Barnes J, Vohra S. Melatonin Interaction Resulting in Severe Sedation. J Pharm Pharm Sci. 2015;18(2):124-131. PMID 26158279
- Spina E, Santoro V, D'Arrigo C. Clinically relevant pharmacokinetic drug interactions with second-generation antidepressants: an update. Clin Ther. 2008;30(7):1206-1227. PMID 18691982
Stack Score
How this pair moves the number.
Effect on the composite score
If both Citalopram and Melatonin 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 documented at /methodology/stack-score.
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