How Long Does DayQuil Last? [Answered]

DayQuil is a medication made for fighting off colds and flu symptoms. Manufactured by Procter & Gamble, this product is sold over-the-counter in pharmacies across the United States without requiring a prescription from your doctor. DayQuil contains many ingredients that are used to decrease inflammation and relieve other common cold symptoms including headaches, fever, body aches, and congestion.

DayQuil comes in the forms of liquid and capsules. Although similar to NyQuil, they are not interchangeable. Here we provide some information on how long does DayQuil last in your system based on each method of use.

How Long Does DayQuil Last?

How Long Does DayQuil Last

A 30 ml or 2 TBSP dosage of DayQuil can last for 4 hours and you will get cough relief for up to 8 hours. The one recommended dose of DayQuil stays for 24 to 36 hours in your bloodstream.

The absorption rate of DayQuil is only 30 minutes in your system so it can start showing effects within 30 minutes after you take it. And you can take a dose of DayQuil after every 4-8 hours. And the good news is you don’t need to take it at bedtime, but you can keep on taking it throughout the day.

DayQuil gel capsules do not dissolve in the stomach like other formulations. Instead, they are formulated to release ingredients that are absorbed into your system by way of your intestines. The active ingredient that most people want to know about is dextromethorphan hydrobromide.

Dextromethorphan hydrobromide (DXM) works as an expectorant and a cough suppressant. It can help your body get rid of mucus and congestion that causes coughing, but if you’ve ever used it recreationally, you know how strong it can be. After ingestion, this is the ingredient that most people are looking for in terms of how long does DayQuil last in your system because it is often used as a recreational drug (see DXM Drug Facts).

Ingredients of DayQuil

  • DayQuil Cough: It contains 10 mg of dextromethorphan and 60 mg of guaifenesin.
  • DayQuil Flu: It contains 4 mg dextromethorphan, 10mg diphenhydramine citrate, and 650mg acetaminophen in every 30 ml dosage.
  • DayQuil Severe: Contains 5 mg dextromethorphan and 25 mg of chlorpheniramine maleate in every 30 ml dosage.
  • DayQuil Cold & Flu: Contains 480mg acetaminophen, 10mg dextromethorphan, 60 mg guaifenesin, as well as 30 mg diphenhydramine citrate per 2 TBSP dosage.

Each taken from the 4-8 hour dosage schedule can last up to 2 days in your system. It is a slow-release formula so it will stay longer in your system.

So now you understand what is the formulation ingredient in DayQuil and now we will dive further in deep and get to know how long all of the above-mentioned drugs stay in your system.

  • Dextromethorphan: The elimination period of dextromethorphan from your system is 33 hours. So it can stay longer in your body.
  • Guaifenesin: It stays in your system for 4-5 hours.
  • Diphenhydramine Citrate: It is long acting sedating antihistamine which can stay up to 5-7 days in your body system, but it depends on how much you take and the kind of kidney function you have. Diphenhydramine citrate is also used as an anti nausea drug.
  • Acetaminophen: It stays in your system for 24-36 hours after the single dosage of DayQuil. Prolonged use will accumulate acetaminophen in your body which can cause liver damage and even death if taken too much.
  • Chlorpheniramine Maleate: The range in which it stays in your system is 2-5 days, but if you take a higher dosage than needed, then you can feel the side effects for a longer time.

So now that we know about all the ingredients of DayQuil and how long they stay in our body system. People usually ask when they can take another dose of DayQuil again, so I will answer this question here. You can take DayQuil after every 4-8 hours if needed.

It is advised not to overdose on DayQuil or any other drug that is used in the formulation of Dayquil because it can be harmful to your body system. All drugs stay in your system depending on the amount you take and your body type. So never take more than the recommended dosage to avoid addiction and overdose.

For instance, if you are using DayQuil cold & flu for two days it can cause side effects like headache, drowsiness (similar experience as taking Xanax), anxiety, stomach problems, vomiting, or sweating too much. Below we will discuss the possible side effects of DayQuil.

How Does DayQuil Work?

As you already know that DayQuil is an over-the-counter drug for treating flu and cold symptoms. There are many different brands of DayQuil, so they contain different formulation ingredients. We already discussed that DayQuil contains dextromethorphan hydrobromide which helps in controlling your cough by reducing the congestion in your throat due to allergies.

Dextromethorphan also helps if you have a cold because it is an expectorant that helps in thinning the mucus and provides relief from congestion.

You should never consume more than 4-8 doses of DayQuil or any other drug per day if you want to avoid addiction and overdose.

When you take one dose of DayQuil it first goes into your stomach and then slowly releases the active ingredients in your body by passing through your stomach and liver. Your liver breaks down these ingredients to a safe form which gets filtered out from your kidneys and you pee it out of your bladder as waste.

The breakdown period for DayQuil or any other drug is determined by how strong or weak your kidney functions are. There are some people who have some kind of kidney problem, so it takes more time for the ingredients to break down in their system because their kidneys cannot filter out the drugs quickly.

The breakdown period also depends on how much you take and your age. A lot of kids under 16 years of age take DayQuil or any other drug which contains dextromethorphan because it doesn’t make them drowsy and they can still go to school.

Also, if you take more than the recommended dosage then the ingredients of DayQuil stay in your body for longer hours or days depending on how much you overdose. In that case, you need to consult a doctor immediately.

What is NyQuil?

NyQuil is a nighttime sleep-aid medicine, and it also contains dextromethorphan which helps you fall asleep by reducing the mental activity of your brain related to its movement. NyQuil contains acetaminophen so you can take one dose if you have a headache or body pain.

NyQuil comes in liquid form which you need to shake well before drinking. Some users ask when they can take the next dose of NyQuil, so if you are taking one or two doses then you can take it after 4-8 hours because it is meant for nighttime use only.

How much DayQuil should take?

Below is the table of recommended doses of DayQuil.

DayQuil TypeAgeRecommended Dosage
Oral capsulesAdults and children 12 years and older2 capsules by mouth every 4 hours. Don’t take more than 8 capsules in a 24-hour period
/Children 4 to 11 years oldAsk your child’s provider
/Children 3 years and youngerDon’t use
Oral tabletsAdults and children 12 years and older2 tablets by mouth every 4 hours. Don’t take more than 10 tablets in a 24-hour period
/Children under 12 years oldAsk your child’s provider
Oral liquidAdults and children 12 years and older30 mL (2 tablespoons) by mouth every 4 hours. Don’t take more than 120 mL (8 tablespoons) in a 24-hour period
/Children 6 to 11 years old15 mL (1 tablespoon) by mouth every 4 hours. Don’t take more than 60 mL (4 tablespoons) in a 24-hour period.
/Children 4 to 5 years oldAsk your child’s provider
/Children 3 years and youngerDon’t use

How long do DayQuil side effects last?

First, we will see what are the common side effects of DayQuil, and then we’ll discuss how long the side effects last in your system.

Common Side Effects:

  • Dizziness
  • Headache and drowsiness
  • Nausea and vomiting
  • Fatigue and irritability
  • Allergic reactions like sneezing, watery eyes, stuffy nose
  • Stomach pain
  • Difficulty sleeping

You can avoid most of these side effects by using DayQuil as per the recommended dosage.

Severe Side Effects:

  • Hives
  • Difficulty in swallowing and breathing
  • Ringing in the ears and skin rashes
  • High fever
  • Rashes
  • Red skin
  • Excessive sleepiness

So if you ever encounter any of these side effects then immediately ask for help by calling 911 or contacting the poison control center. Note: It is studies that if you take grapefruit with dextromethorphan, it can boost the level of dextromethorphan in your body by 10 times. So be careful if you are taking DayQuil while drinking grapefruit juice.

Can I skip the dose?

If your doctor recommended taking your doses regularly then it is better to not skip any doses. But, if you are feeling much better and don’t need medication anymore then it is safe to stop taking the medication. Moreover, if you are using other medications then you need to consult with your doctor.

Can I Mix DayQuil With Alcohol?

Mixing DayQuil with alcohol can cause nausea, vomiting, stomach pain, and drowsiness. It’s better not to mix the two because it will make you feel sick or sleepy rather than helping in getting rid of your cold symptoms.

Can I Mix DayQuil With Other Drugs?

When you take DayQuil with other drugs then it will stay in your bloodstream longer than usual because your liver and kidneys are not able to function properly due to the drugs you mix with them. Your body will start to work slowly and it may take a week or a month for your body to get back to its normal state. So, avoid mixing any drug with DayQuil if you want it to work quickly and let your body system recover as soon as possible.

How to Take DayQuil the Proper Way?

If you are not sure how to properly take your medication then there are some tips that you can follow. But the first thing first is that you should always take medications according to your doctor’s prescription. Below are some ways that you can follow to take medication safely.

Follow the Prescription of your Doctor or Read the Label

The first thing is that you need to always follow the prescription of your doctor. Your doctor has prescribed you DayQuil for a reason and it’s important to follow their direction. That said, if you want some other information on how long the medication lasts in your system, then there are some other things that can be done to get this information. You could look at the label on the package of DayQuil and see what it says.

Medications can be broken down into three categories: Drugs, Biologics, and Vaccines. These are the things that help you get through the day when you want to feel better or prevent your cold or flu symptoms. The ingredients in each of these will change how long they last, so it’s important to understand what you are taking. This can help you know how long DayQuil will stay in your body after you take it.

Use a Measuring Lid of a Bottle

Always take your medication with recommended measurements. You can find measuring lids that come with DayQuil or you can purchase them separately. This makes it easier because there are dosage lines on the bottle to make sure you are using the right amount.

Take an Antiemetic to Prevent Nausea and Vomiting

If your doctor recommended taking medication to prevent nausea and vomiting then it is important to take the antiemetic first. But if you are not sure whether to take an antiemetic or not, it is better to consult your doctor once again before taking any medication.

Tell your Medical History to your Doctor

It is very important that you should tell your doctor about your medical history, allergies you have and other medications you are taking. These things help your doctor to know how DayQuil can affect you so that they can recommend the best treatment plan for you.

Factors that can Affect the Long Lasting of DayQuil in your System

When you take any kind of medication, there are some factors that affect the lifespan of the medicine in your system. Below are the factors that can impact the half-life and full life of any medicine that you take.


Age is one of the factors that will determine how long DayQuil will last in your system. Generally, an elderly person will need a longer period of time to get rid of the medicine from their body as compared to children and young adults. If you are taking any other medication along with DayQuil then you should consider this factor as well. The reason behind this is that it would be difficult for your liver and kidneys to process the medicine when you take other medications.

Your Sex

Generally, women have a longer lifespan than men because their body systems work slower than men’s. But the problem with women is that they need more time to recover from any injury or accident that may occur. So, in this case, it would be better to consult your doctor so that you can get the appropriate or precise dose of medication.

Weight or Body Mass

Your weight is also one of the significant factors that play an important role in determining how long any medicine will last in your system. If you are a person who has more body mass then it will take more time for the medicine to travel through your body. And if you are someone who is very lean then it won’t be that much difficult for your body to absorb the medicine quickly.

Your Metabolism Rate

Another factor that can affect how long DayQuil lasts in your system is the metabolism rate. If you have a higher metabolism rate, then it would take less time for your liver and kidneys to break down the medicine so that it can be excreted from your body.

Alcohol Consumption

If you are a person who drinks alcohol regularly or even occasionally then DayQuil will not last as long in your system as compared to someone who doesn’t drink at all. People who drink alcohol have a higher metabolism rate because it is already broken down by the liver before your body takes it. So, in this case, you must ask your doctor for a recommended dosage of medication that will be suitable for you.

Your Eating Habits

If you eat food regularly then the medicine will last longer in your system as compared to those who skip their meals. So, if you had a cup of coffee and pretzels before taking your medication then it would take more time for the medicine to break down as compared to someone who eats a meal before taking any medication.

Body Fat Percentage

If you have a higher percentage of body fat, then it might take more time for the medicine to break down because fatty tissues contain enzymes that help in breaking down the medicine. And if your body fat is very low then it may not affect how long DayQuil will last in your system.

Food Consumption Before and After Taking Medicine

If you are basically a person who eats many times in a day then it’s better to take your medicine after eating when your stomach is full. You can ask your doctor about which food items will be preferable when taking the medicine.

Basal metabolic rate (BMR)

This factor describes how quickly your body turns food into energy. A high BMR means that it will take less time for the medicine to break down and be processed by your liver and kidneys. But if you have a low metabolism rate then it might take longer for the medicine to stay in your system as compared to someone who has a high metabolism rate.

Kidney Health

If you have a healthy and clean kidney, then it will take less time for the medicine to break down and be removed from your body. But if you have poor kidneys then it might take longer for DayQuil to leave your system because of toxicity in your bloodstream which would affect the working of other organs as well.

Liver Health

If you have a healthy liver then it might take less time for the medicine to break down and be processed by your body. But if you have a poor liver function, then it will take more time for the medicine to break down because your liver would fail in doing its job of cleaning your bloodstream.

Body Mass Index

It is also one of the important factors that play an important role when it comes to determining how long does DayQuil lasts in your body. If you are a person who has more body fat then chances are, it would take more time for the medicine to leave your system than someone who is lean and healthy with less body fat.


When it comes to the dosage, it is very important for you to ask your doctor what is an appropriate dose that would suit you. It’s better not to take more or less than the prescribed dose because it will affect how long DayQuil lasts in your system.


How long does DayQuil last in your system?

DayQuil will last in your system for around four hours. It is important to note that everyone’s body is different and will metabolize the medication differently, so it is always best to ask a doctor if you are unsure.

When will DayQuill expire?

The DayQuil expiration date will be printed on the bottle. It is typically good for around four years past the manufacture date.

What are the active ingredients of DayQuil?

DayQuil’s active ingredients include acetaminophen, dextromethorphan HBr (cough suppressant), phenylephrine HCl (nasal decongestant), and doxylamine succinate (nighttime cold/allergy symptom reliever).

What is DayQuil’s dosage?

The typical dosages for adults and children over age 12 are one tablet every four to six hours as needed for fever or pain, or two tablets every eight hours. Children 6-12 years old should take half the adult dose. Two teaspoons of syrup can be taken every four to six hours as needed for coughs. Do not give more than eight doses in 24 hours.

Which medications can potentially interact with DayQuil?

DayQuil is a combination of four different medications, so it is important to be wary of interactions between these components and any other medication being taken. Acetaminophen can potentially interfere with certain blood thinners, diuretics, and cholesterol-lowering drugs. Dextromethorphan should not be consumed alongside monoamine oxidase inhibitors (MAOI), opioids, or risperidone. Phenylephrine increases the risk for high blood pressure while phenytoin may increase phenylephrine levels in the body. Finally, doxylamine can cause drowsiness when used together with other sedating drugs like antihistamines, tranquilizers, antidepressants, opioids, and alcohol.

What are the side effects of DayQuil?

Some potential side effects include increased or uneven heart rate; anxiety; confusion; excitability; fast heartbeat; loss of appetite; nausea and vomiting; nervousness; restlessness; trouble sleeping (insomnia); unusual tiredness or weakness (fatigue); and cold symptoms such as stuffy nose (stuffy nose), sneezing, cough (mild cough), or sore throat (sore throat).

Why is it important to be mindful of interactions when taking DayQuil?

It is important to be mindful of drug interactions when taking DayQuil for two reasons: it can potentially lead to an overdose taken with other medicines that also interferes with breathing, and it can enhance the effects of another drug when taken together.

What are some warnings for people who should avoid taking DayQuil?

People who have an ulcer or other stomach problems; high blood pressure; thyroid disease; glaucoma; prostate problems; heart problems; diabetes; trouble urinating due to an enlarged prostate gland (prostate hypertrophy); and asthma should not take DayQuil. People who are pregnant or breastfeeding should also avoid using DayQuil unless specifically instructed by a doctor.

Can children consume DayQuill?

Yes, but dosage instructions depend on age and weight. It is important to always check dosage instructions before administering medicine to small children.


In conclusion, it is important to be mindful of interactions with certain medications and potential side effects when taking DayQuil. Always follow dosage instructions for children or if pregnant or breastfeeding. Follow the expiration dates on medication packaging very closely; this will decrease the chance of overdose.

Disclaimer: This article is for informative purposes only and does not serve as medical advice. Please visit your doctor or pharmacist before beginning any new medication regimen.

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