How Long Does Nyquil Last? (2024)

Nyquil is an over-the-counter (OTC) medicine used to treat symptoms of flu, colds, and other respiratory illnesses, including the following:

• Congestion
• Sneezing
• Coughs

It is available as syrup and as liquid caps.

Nyquil is typically combined with antihistamines, cough suppressants, and pain relief medications for maximum effectiveness.

It contains several active ingredients, including the following:

• Acetaminophen (pain relief)
• Dextromethorphan (cough suppressant)
• Doxylamine succinate (antihistamine)
  

Each ingredient has a different duration of action (how long it lasts). How long Nyquil's effects last varies from person to person, depending on personal factors and the formulation used.

This article will cover Nyquil, what it treats, its precautions, and alternative approaches.

How Long Does It Take for Nyquil to Work?

Most people will feel the benefits of Nyquil within 30 minutes of taking the medicine.

Nyquil typically provides relief between 4 and 6 hours.

Follow the manufacturer's or your healthcare providers' dosage instructions to avoid adverse effects or harm. Taking too much of this medicine or too often may have adverse and dangerous effects.

It's best to consult with a pharmacist if you are concerned about Nyquil. A pharmacist can give advice tailored to your particular health situation and the medications or supplements you take.

What’s a Normal Nyquil Dosage for Adults?

Your dosage instructions may be different based on your healthcare provider's instructions. For personalized advice, it is best to consult your healthcare provider or read and adhere to the instructions on the package.

• Nyquil syrup: Adults may take 30 milliliters (mL)—2 tablespoons—of liquid every 6 hours or as needed. Shake well before use. Pour out the exact amount with the medicine measuring cup provided.
• Nyquil liquid caps: Take two capsules by mouth every 6 hours as necessary. You may take it with or without food with a glass of water.

Avoid taking more than the recommended dose of Nyquil or multiple medications with similar ingredients, as this can lead to an overdose. Take at most four doses of Nyquil in 24 hours.

Is There Nyquil for Children?

Nyquil has liquid formulations tailored for use by children. These products are specifically designed to relieve symptoms from colds and flu in children 6 years and older.

Children's Nyquil differs significantly from that intended for adults in both dose and formulation. Follow the instructions carefully to give the ideal dosage based on your child's age and weight criteria.

Consult a healthcare provider or pediatrician first before giving Nyquil to children.

Side Effects & Precautions

Side effects of Nyquil may include, but are not limited to, the following:

• Drowsiness
• Sedation
• Difficulty urinating
• Dry mouth, throat, or nose
• Lightheadedness
• Nausea
• Upset stomach
• Blurred vision
  

Alcohol: Drinking alcohol while taking Nyquil may increase your risk for liver damage and make you feel drowsy.

Coordination: Nyquil can also impair coordination—do not drive or operate machinery while on this drug.

Pregnancy and breastfeeding: Nyquil may pose risks to the fetus pregnant people and the infants of breastfeeding people. Hence, if you are pregnant or nursing, speak to your healthcare provider before taking any over-the-counter (OTC) drug, including Nyquil.

People with certain medical issues should not use Nyquil. Let your healthcare provider know before taking Nyquil, especially if you have the following:

• Liver or kidney disorders
• Asthma
• High blood pressure
• Diabetes
• Thyroid disorders
• Glaucoma
• Prostate enlargement
  

Nyquil may also interact with some medications like the following:

• MAO inhibitors (antidepressants)
• Sedatives
• Tranquilizers
  

What to Do If You Took Too Much Nyquil

Signs of a Nyquil overdose may include the following:

• Severe drowsiness
• Confusion
• Difficulty breathing
  

Alternatives to Managing Symptoms

While Nyquil may be safe and effective, other alternatives to treat your symptoms include the following:

• Rest:Get plenty of sleep, limit strenuous activity, and take it easy until your symptoms improve.
• Good hygiene:Wash your hands often and cover your mouth and nose while coughing or sneezing. Avoid physical contact with others to prevent illness from spreading. Consider wearing a mask around others while ill.
• Stay hydrated:Drink plenty of fluids throughout the day to reduce mucus and soothe sore throat symptoms. These include water, herbal tea, and warm broth. Hydration thins mucus and soothes sore throats.
• Use saline nasal sprays or drops:Saline nasal sprays and drops can temporarily relieve congestion by moisturizing the nasal passages. These products are available at your local pharmacy and should be used as directed. You could also use throat lozenges to help soothe your throat.
• Warm salt water gargle:Combine 1 teaspoon of warm water with a pinch of salt to gargle and reduce inflammation.
• Use a humidifier:Increasing humidity through humidifiers or showers can relieve congestion and coughing symptoms. Remember to clean your humidifier and change the water daily.
• Avoid possible irritants:Avoid smoke, strong fumes, and other sources that aggravate symptoms or slow recovery to ensure a rapid recovery.
  

Summary

Nyquil is an OTC drug used to treat flu and cold symptoms. It begins to work within 30 minutes after ingestion and lasts 4 to 6 hours.

Please get in touch with your healthcare provider if symptoms like severe pain, fever, or breathing difficulty worsen. These could be signs that something more serious is going on.

Pregnant or breastfeeding people who take certain medications or have had alcohol need to avoid using Nyquil.

Always seek personalized medical advice and guidance tailored to your specific situation.