What You Need to Know About NyQuil

NyQuil is a very popular medication used to treat cold and flu symptoms. Find out if it is right for you and your symptoms.

Pouring some cough syrup
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Active Ingredients (in each 15ml tablespoon)


  • Adults - Two tablespoons every six hours as needed for cold and flu symptoms. Do not take more than four doses in 24 hours.
  • Children - Ask a healthcare provider.

Uses for Nyquil

Temporary relief of cold and flu symptoms including:

  • Cough
  • Sore Throat
  • Headache
  • Minor aches and pains
  • Fever
  • Runny nose
  • Sneezing

Side Effects of Nyquil

  • Drowsiness
  • Excitability, especially in children


  • Do not consume if you drink more than three alcoholic drinks a day. Acetaminophen can cause liver damage. Ask your healthcare provider if you should take acetaminophen if you regularly drink more than three alcoholic drinks per day.
  • Do not use with other medications containing acetaminophen.
  • Do not use this medication if you are taking an MAOI (medication for depression, psychiatric, emotional conditions or Parkinson's disease) or for two weeks after stopping an MAOI.

Ask a Healthcare Provider Before Use

  • If you have glaucoma
  • If you have a cough that produces a lot of mucus
  • If you have a breathing problem or chronic cough that is caused by asthma, smoking, chronic bronchitis or emphysema
  • If you have trouble urinating because of an enlarged prostate
  • If you are taking sedatives or tranquilizers
  • If you are pregnant or breastfeeding


Stop use and ask a healthcare provider if:

  • Pain or cough worsens or lasts more than seven days
  • Fever worsens or lasts more than three days
  • Redness or swelling is present in area causing pain
  • New symptoms occur
  • Cough returns or occurs with a rash or headache that won't go away

Other NyQuil Information

Do not take this product when you have to operate machinery, drive a vehicle or perform other tasks that require alertness.

Nyquil is likely to make you very drowsy; be sure you can devote time to sleep before taking this product.

Frequently Asked Questions

  • Why does NyQuil make me sleepy?

    Ingredients in Nyquil that control cough and congestion have side effects that cause you to feel sleepy. Dextromethorphan, a cough suppressant in Nyquil, and doxylamine succinate, an antihistamine, cause drowsiness.

  • How often can I take NyQuil?

    You can take two NyQuil LiquiCaps every six hours or 30 ml of NyQuil Liquid every six hours. Do not take more than four doses of NyQuil in a 24-hour period.

  • Can I take NyQuil for COVID?

    Cold medications such as NyQuil may help relieve some symptoms of COVID such as coughing or sore throat, but they will not cure you of the illness. If you're taking any other medications, check with your doctor first since there may be some interactions. Also, do not take any additional acetaminophen (including Tylenol) while using NyQuil.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. National Library of Medicine. Label. Vicks Nyquil Cold and Flu - acetaminophen, dextromethorphan hydobromide, and doxylamine succinate capsule, liquid filled. DailyMed.

  2. Vicks. Vicks Nyquil FAQ.

  3. U.S. Food & Drug Administration. Acetaminophen: avoiding liver injury.

  4. Memorial Sloan Kettering Cancer Center. Managing COVID-19 at Home.

By Kristina Duda, RN
Kristina Duda, BSN, RN, CPN, has been working in healthcare since 2002. She specializes in pediatrics and disease and infection prevention.