Aspirin and Melatonin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Jul 11, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Aspirin
Melatonin
No brand names on record
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
An increased risk of suppression of endogenous melatonin levels
Interaction Deep Dive
Exert caution when melatonin is coadministered with acetylsalicylic acid (a prostaglandin synthesis inhibitor (NSAIDs)). Acetylsalicylic acid given in the evening may suppress endogenous melatonin levels in the early part of the night by up to 75%. If possible, avoid administration of NSAIDs in the evening1.
Why it happens (mechanism)
Suppression of endogenous melatonin levels
Common questions
Can I take Aspirin and Melatonin together?
An increased risk of suppression of endogenous melatonin levels Always confirm with your pharmacist or prescriber before making any change.
How serious is the Aspirin and Melatonin interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
- Can I Take Glucoven With Baby Aspirin, Metoprolol, and Losartan?
- Is Hibiscus Tea Safe With Metoprolol, Losartan, and Aspirin?
- Is It Risky to Take Low Dose Aspirin With Nattokinase?
- Is Melatonin Appropriate for a 15-Year-Old to Take for Sleep?
- Can You Take Melatonin With Temazepam?
- Can You Take Eliquis With Melatonin?
Questions for your pharmacist
- Does my dose of Aspirin or Melatonin need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: Slenyto oral prolonged-release tablets, melatonin oral prolonged-release tablets. RAD Neurim Pharmaceuticals EEC SARL (per EMA), Paris, France, 2025. DailyMed
Keep reading about Aspirin
Keep reading about Melatonin
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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