How to Take NyQuil: Side Effects, Dosage
How to take NyQuil: proper dosage, common side effects, and precautions for nighttime cold and flu relief.
Not medical advice. Speak with a healthcare professional before using any medication.
Reviewed by:
Updated Feb, 15
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Information sourced from FDA-approved prescribing information and peer-reviewed medical references.
How to Take NyQuil
How to Take NyQuil
Per OTC labeling, NyQuil is intended for nighttime use only, as it contains a sedating antihistamine. The following reflects standard label instructions.
- Per OTC labeling, adults and teens 12+ years: 30 mL (2 tablespoons) of the liquid every 6 hours as needed, or 2 LiquiCaps every 6 hours. Per OTC labeling, do not take more than 4 doses in 24 hours.
- Per OTC labeling, children under 12: Standard NyQuil products are not recommended for children under 12. Use only children's formulations labeled for their specific age group, and follow labeled doses exactly.
- Per OTC labeling, for nighttime use: Because NyQuil contains a sedating antihistamine, take it only when you are able to remain at rest and avoid driving or operating machinery.
- Per OTC labeling, how to measure: Use the included dosing cup for liquid forms. Do not use household spoons, which do not measure accurately.
- Per OTC labeling, NyQuil may be taken with or without food.
- Per OTC labeling, if you miss a dose: Take it only if you still need it for nighttime symptoms and can remain at rest afterward. Otherwise, wait for the next scheduled bedtime dose.
Per OTC labeling, take NyQuil exactly as the package directs and keep doses spaced at least 6 hours apart.
Warnings Before Taking NyQuil
- Per OTC labeling, avoid alcohol while taking NyQuil; it increases sedation and the risk of liver injury due to the acetaminophen component.
- Per OTC labeling, do not combine with other products containing acetaminophen, as this can result in acetaminophen overdose.
- Per OTC labeling, check with your doctor if you have liver disease, glaucoma, chronic bronchitis, or are taking sedatives or tranquilizers before use.
- Per OTC labeling, avoid driving or operating machinery until you know how this medication affects you.
NyQuil Side Effects
Common
Mild
Drowsiness
Per OTC labeling, NyQuil causes drowsiness due to its antihistamine (doxylamine) component. This is an expected effect; do not drive or operate heavy machinery while it is active.
Per OTC Drug Facts labeling. If symptoms persist or worsen, stop use and consult a healthcare provider.
Normally lasts for:
4–8 hours
Common
Mild
Dry Mouth
Per OTC labeling, reduced saliva production (dry mouth) may occur due to the anticholinergic effects of the antihistamine component.
Per OTC Drug Facts labeling. If symptoms persist or worsen, stop use and consult a healthcare provider.
Normally lasts for:
4–6 hours
Common
Mild
Dizziness
Per OTC labeling, some people may feel lightheaded or unsteady, particularly when changing positions, due to NyQuil's sedating effects.
Per OTC Drug Facts labeling. If symptoms persist or worsen, stop use and consult a healthcare provider.
Normally lasts for:
1–4 hours
Occasional
Mild
Upset Stomach
Per OTC labeling, NyQuil can occasionally cause mild nausea or stomach discomfort.
Per OTC Drug Facts labeling. If symptoms persist or worsen, stop use and consult a healthcare provider.
Normally lasts for:
1–3 hours
Rare
Mild
Blurred Vision
Per OTC labeling, the antihistamine ingredient may temporarily cause blurred vision due to anticholinergic effects.
Per OTC Drug Facts labeling. If symptoms persist or worsen, stop use and consult a healthcare provider.
Normally lasts for:
2–6 hours
Occasional
Moderate
Next-Day Grogginess
Per OTC labeling, because NyQuil contains a sedating antihistamine, residual drowsiness upon waking has been reported. Avoid driving or operating machinery if next-day grogginess is present.
Per OTC Drug Facts labeling. If symptoms persist or worsen, stop use and consult a healthcare provider.
Normally lasts for:
4–12 hours
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What If You Forgot to Take NyQuil
What If You Forgot to Take NyQuil?
Per OTC labeling, if you miss a dose of NyQuil:
Per OTC labeling, if you still need it for nighttime symptoms and are able to remain at rest for several hours, you may take it when you remember.
If you are starting your day or need to be alert, skip the dose. Per OTC labeling, NyQuil should not be taken when you need to drive or be active.
Per OTC labeling, do not double up. Resume your usual nighttime dose the next evening if symptoms continue.
What If You Took Too Much NyQuil
What If You Took Too Much NyQuil?
Contact Poison Control at 1-800-222-1222 right away. Per OTC labeling, NyQuil contains acetaminophen; overdose can cause serious liver damage. It also contains doxylamine (antihistamine) and dextromethorphan, which can cause rapid heartbeat, excessive drowsiness, and seizures in overdose.
Call Poison Control (1-800-222-1222) for immediate guidance, even if symptoms are not yet present.
- If symptoms such as severe drowsiness, rapid or irregular heartbeat, difficulty breathing, or seizures occur, seek emergency medical care immediately.
- Per OTC labeling, avoid alcohol or any other medicines that cause drowsiness until evaluated.
- Keep this and all medications out of reach of children.
How Much Does NyQuil Cost
NyQuil Cost With Insurance
NyQuil is an over-the-counter product. Most insurance plans do not cover it directly. Reimbursement may be available through a flexible spending account (FSA) or health savings account (HSA) if your plan includes OTC benefits.
- Most insured shoppers pay retail pricing for NyQuil.
- Store-brand equivalents may be available at lower cost and may contain similar active ingredients.
Contact your insurer to confirm whether OTC cold remedy reimbursement applies under your plan.
How Much Does NyQuil Cost without Insurance
NyQuil Cost Without Insurance
NyQuil is an over-the-counter product available at most U.S. pharmacies and retailers. Prices vary by bottle size, formulation (liquid vs. LiquiCaps), and whether you choose brand-name NyQuil or a store-brand equivalent. Store-brand versions may offer similar active ingredients at a lower price.
Contact your local pharmacy for current pricing. Prices are subject to change and vary by location.
Resources:
https://www.fda.gov/media/143025/download
https://www.vicks.com/en-us/safety-and-faqs/product-safety/nyquil
https://medlineplus.gov/druginfo/meds/a682544.html
https://www.drugs.com/mtm/vicks-nyquil-cough.html
https://www.mayoclinic.org/drugs-supplements/dextromethorphan-oral-route/description/drg-20068661
