How Long After Tylenol Can I Take Nyquil (And Why)?

How Long After Tylenol Can I Take Nyquil (And Why)?

Exact Answer: 8 Hours

Tylenol is an American brand of drugs whose active ingredient is acetaminophen, commonly also known as paracetamol that is used for reducing fever, pain, relieving symptoms of allergies, cold, cough, and flu.

Nyquil is an antihistamine that causes drowsiness by blocking histamine and its effects, thereby treating symptoms such as sneezing, itchy, watery eyes, runny nose, itchy throat and causes sedation.

It is basically medicine for treating cold and flu which helps people to fall asleep so that one doesn’t stay awake all night coughing.

However, Nyquil contains Tylenol. Thus, one must not consume both simultaneously as doing so will lead to doubling up on the Tylenol and thus, increasing the risks of toxicity and potential liver damage.

How Long After Tylenol Can I Take Nyquil

How Long After Tylenol Can I Take Nyquil?

Acetaminophen-induced Hepatotoxicity’s SymptomsDuration After Ingestion
Anorexia, nausea, vomiting, and malaise0.5 – 24 Hours.
Abdominal pain, hypotension and hypertension18 – 72 Hours
Continued nausea, vomiting, and abdominal pain72 – 96 Hours

One should never take Tylenol and Nyquil together as both products contain acetaminophen as their active ingredient. If both are consumed at the same time, the acetaminophen in them might mix and could exceed the allowable daily dose, causing a fatal condition called acetaminophen’s induced hepatic necrosis.


Excessive acetaminophen in the body could lead to acetaminophen-induced hepatotoxicity. Along with the above-mentioned side effects, one might also experience excessive dizziness, sedation, impaired thinking, and blurred vision.

Thus, to avoid such complications from arising, care must be taken not to consume both at the same time.

Why Does It Take Longer After Tylenol To Have Nyquil?

Even though Nyquil comes in a variety of formulation that contains several ingredients, all of these formulations contain acetaminophen i.e. Tylenol so tremendous caution must be taken if consuming both on the very same day. The doctor’s advice is essential.

Different medications consist of different ingredients. Combining two medications having similar ingredients can drastically increase one’s chances of getting an overdose which could lead to unnecessary side effects and risks.

It is essential not to exceed the maximum daily dosage of acetaminophen which can happen quite easily if one consumes both Tylenol and Nyquil one after the other immediately. The maximum allowable dosage of Tylenol is 1000mg per dose and 4000mg per day.

Taking more than recommended dose may lead to significant liver damage.

Acetaminophen is primarily processed in the liver. The liver breaks down most of the acetaminophen in a normal dose and eliminates it in the urine.

A small portion of the drug is converted to a byproduct that is extremely toxic to liver cells. When one takes too much acetaminophen all at once, this toxic breakdown of byproduct can build up and cause damage to the liver.


Furthermore, children younger than 4 years must not be given Nyquil as it can drastically reduce alertness. Pregnant patients shouldn’t use it as the toxins in it can harm the unborn baby.

Patients with phenylketonuria should also avoid these medications. Utmost care must be taken not to consume alcohol at the same time, as drinking alcohol may potentially increase the risk of side effects if consumed while taking Tylenol.


Acetaminophen is a safe and very effective drug. It is the main ingredient of both Tylenol and Nyquil.

However, when consumed together the result can be quite fatal. One must keep tabs on the amount of acetaminophen in each drug along with the duration of consumption to avoid inadvertently taking too much of it.

One might damage the liver with long-term overuse of acetaminophen in Tylenol. If one is susceptible to constant liver or stomach issues, consumption of acetaminophen must not be done without a prescription from the doctor.

Thus, being careful when taking multiple products containing acetaminophen and calculating your daily doses to avoid consuming excess is of vital importance. If unsure, always ask a pharmacist for assistance regarding how to safely consume combinations of medicine that include acetaminophen.


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26 thoughts on “How Long After Tylenol Can I Take Nyquil (And Why)?”

  1. The detailed explanation is quite helpful in understanding the potential dangers associated with these medications.

  2. Avatar of Collins Michael
    Collins Michael

    Thank you for this valuable information. We must be extremely careful with the consumption of these medications.

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