Combination

Mixing NyQuil and Tylenol PM

CombinationCombination
Verdict

Unsafe · Acetaminophen twice

NyQuil and Tylenol PM both contain acetaminophen (Tylenol). This is the overdose people take by accident: each product stays under its own daily limit, and together they can go past it. Too much acetaminophen damages the liver, and symptoms may not start for 12 hours or more, so feeling fine does not mean the dose was fine. Every acetaminophen label says not to take it with any other product that contains acetaminophen.

  1. Take one of them, not both. Check the Drug Facts box on each: acetaminophen should appear on only one of them.
  2. Already took both and went past the daily limit? Call Poison Control now: 1-800-222-1222. Even if you feel fine. There is an antidote, and treatment within 8 hours gives a very good chance of recovery.
What “Unsafe” means
In an emergency, call 911911Never Use AlonePoison Control
What to do
  • Say what was taken and how much.Responders need it, and in most US states Good Samaritan laws protect both of you from drug possession charges when you call for an overdose.
  • Unresponsive: put them on their side, tilt the head back, and stay until help arrives.Never leave someone alone to “sleep it off”.
  • Never Use Alone 1-800-484-3731Stays on the line and sends help if you stop responding.
  • Full steps: what to do if it is already happeningOverdose signs, the recovery position, what to say on the call, and whether you can be charged for making it.
  • Poison Control 1-800-222-1222Free and 24/7, for “is this bad?” before it becomes an emergency.

Can you take NyQuil with Tylenol PM?

NyQuil contains acetaminophen, DXM and doxylamine. Tylenol PM contains acetaminophen and diphenhydramine. NyQuil and Tylenol PM both contain acetaminophen (Tylenol). This is the overdose people take by accident: each product stays under its own daily limit, and together they can go past it. Too much acetaminophen damages the liver, and symptoms may not start for 12 hours or more, so feeling fine does not mean the dose was fine. Every acetaminophen label says not to take it with any other product that contains acetaminophen. MixSafe rates NyQuil with Tylenol PM as "Unsafe" — risk of serious physical or psychological harm. Not recommended under any circumstances. Sources: the Drug Facts labels on DailyMed and Poison Control. 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.
Tylenol PM
Acetaminophen + Diphenhydramine.

Acetaminophen twice

Unsafe

NyQuil + Tylenol PM

What to do
  1. 01Take one of them, not both.Check the Drug Facts box on each: acetaminophen should appear on only one of them.
  2. 02Already took both and went past the daily limit? Call Poison Control now: 1-800-222-1222.Even if you feel fine. There is an antidote, and treatment within 8 hours gives a very good chance of recovery.
Signs it is happening
  1. Often nothing at firstThat is why it gets missed. Nausea, vomiting, sweating and stomach pain can follow; yellow skin or eyes mean the liver is already hurt.
Why this happens

NyQuil and Tylenol PM both contain acetaminophen (Tylenol).

This is the overdose people take by accident: each product stays under its own daily limit, and together they can go past it. Too much acetaminophen damages the liver, and symptoms may not start for 12 hours or more, so feeling fine does not mean the dose was fine. Every acetaminophen label says not to take it with any other product that contains acetaminophen.

Sources
  • Vicks NyQuil Cold & Flu, Drug Facts label: "Do not use with any other drug containing acetaminophen." DailyMed. dailymed.nlm.nih.gov
  • Acetaminophen overdose. MedlinePlus Medical Encyclopedia. medlineplus.gov

Antihistamine twice

Unsafe

NyQuil + Tylenol PM

What to do
  1. 01Take one of them, not both.Daytime cold medicines usually leave the antihistamine out, if that is the part you do not need.
  2. 02Seizures, hallucinations, or someone you cannot wake: call 911.Short of that, Poison Control (1-800-222-1222) can tell you whether what was taken needs a hospital.
Signs it is happening
  1. Confusion, or seeing and hearing things that are not there
  2. A racing or pounding heartbeat
  3. Hot, dry, flushed skin, and not being able to pee
Why this happens

NyQuil and Tylenol PM both contain a sedating antihistamine (doxylamine in NyQuil and diphenhydramine in Tylenol PM).

Together they add up: heavier drowsiness, confusion, a racing heart and trouble peeing, and at higher amounts hallucinations and seizures. Poison Control's advice is not to take two antihistamines at the same time.

Sources
  • Safe use of antihistamines. Poison Control (National Capital Poison Center). poison.org
  • Benadryl Allergy, Drug Facts label: "Do not use with any other product containing diphenhydramine, even one used on skin." DailyMed. dailymed.nlm.nih.gov
  • FDA warns about serious problems with high doses of the allergy medicine diphenhydramine (Benadryl). FDA, September 2020. fda.gov
Sources

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.

Think this is wrong, or know a better source? Send it.

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