Mixing Melatonin and NyQuil
Low risk, increased effect
Low risk of harm, but the effects amplify each other. Doses that are fine alone can be far too much together.
Can you take Melatonin with NyQuil?
NyQuil contains acetaminophen, DXM and doxylamine. The most concerning part is Melatonin with NyQuil (Doxylamine): additive sedation. Both are used as sleep aids, and stacking them mostly adds next-day grogginess rather than benefit. The doxylamine in NyQuil is checked as diphenhydramine (Benadryl), the closest drug MixSafe has data for, so this answer and any dose in it are diphenhydramine's. MixSafe rates Melatonin with NyQuil as "Low risk, increased effect" — low risk of harm, but the effects amplify each other. Doses that are fine alone can be far too much together. Sources: the Drug Facts labels on DailyMed and MixSafe research. Educational information, not medical advice.
What is in it
- NyQuil
- Acetaminophen + DXM + Doxylamine. Doxylamine is checked as diphenhydramine (Benadryl): both are sedating antihistamines of the same kind. NyQuil Severe also contains phenylephrine, a decongestant MixSafe has no data for.
Ingredient by ingredient
Melatonin + NyQuil (Doxylamine)Low risk, increased effect
The doxylamine in NyQuil is checked as diphenhydramine (Benadryl), the closest drug MixSafe has data for, so this answer and any dose in it are diphenhydramine's.
Low risk of harm, but the effects amplify each other. Doses that are fine alone can be far too much together.
Additive sedation. Both are used as sleep aids, and stacking them mostly adds next-day grogginess rather than benefit.
Sources: Melatonin Interactions Checker. Drugs.com · Melatonin + Xanax: Can You Take Them Together? · Melatonin and SSRIs
Melatonin + NyQuil (Acetaminophen)Low risk, no synergy
Neither substance is expected to meaningfully change the other. Both still carry their own individual risks.
No specific interaction is documented. Acetaminophen's main risk is dose-dependent liver injury, so the thing to watch in any combination is total daily intake across all products (roughly 4g/24h) and anything else straining the liver.
Sources: Prescott LF. Paracetamol, alcohol and the liver. Br J Clin Pharmacol. 2000 · Acetaminophen: A Liver Killer or Thriller
Melatonin + NyQuil (DXM)Low risk, no synergy
Neither substance is expected to meaningfully change the other. Both still carry their own individual risks.
No specific interaction is documented. Melatonin is a mild sedative, so the general rule is that it adds drowsiness to anything else sedating and does little to anything else.
Sources: Melatonin Interactions Checker. Drugs.com · Melatonin + Xanax: Can You Take Them Together? · Melatonin and SSRIs
- Vicks NyQuil Cold & Flu LiquiCaps, Drug Facts label. DailyMed, December 2025. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=efe4e649-7514-32dd-e053-2995a90a0492
Ingredient lists checked 2026-09-27. Formulas change and store brands differ, so the Drug Facts box on your own packet is the final word.
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