This combination medication is used to temporarily treat symptoms caused by the common cold, flu, allergies, or other breathing illnesses (such as sinusitis, bronchitis). Dextromethorphan is a cough suppressant that affects a certain part of the brain, reducing the urge to cough.

The typical adult dosage of NyQuil Cold & Flu is 2 capsules or 30 mL by mouth every 6 hours as needed. Don't take more than 4 doses (8 capsules or 120 mL) in 24 hours.

Taking NyQuil can make people drowsy and fall asleep, which is the major side effect of the drug. The duration and quality of sleep can vary depending on the person. Other, rarer, side effects are mainly due to the acetaminophen component and can include: Skin reddening.

How long does Nyquil's drowsiness last? Nyquil's active ingredient, doxylamine, which has antihistamine and sedating effects, can lead to sleepiness. Nyquil can cause different degrees of sleepiness, depending on the individual lasting anywhere from 4 to 6 hours on average.

How long does Nyquil's drowsiness last? Nyquil's active ingredient, doxylamine, which has antihistamine and sedating effects, can lead to sleepiness. Nyquil can cause different degrees of sleepiness, depending on the individual lasting anywhere from 4 to 6 hours on average.

NyQuil takes about 30 minutes to start working. It can be taken at any time of day, but be aware that it can cause drowsiness. So you may need to aveoid using it during the day if it makes you too sleepy. NyQuil can be taken with or without food, but it may interact with other medications you take.

Though NyQuil contains ingredients like doxylamine that are often prescribed for sleep, relying on NyQuil for sleep is not advised. Besides doxylamine, NyQuil contains other active ingredients like alcohol that should not be used for sleep. And even doxylamine is only meant as a short-term sleep aid.

Is it bad to take NyQuil to sleep? You should only use NyQuil as directed on the label. NyQuil is used to treat the symptoms of the cold and flu and not as a sleeping agent for insomnia. However, it can help you feel better if you have a cold or flu because it can treat your symptoms which will help you rest easier.

"When used as directed, NyQuil does not present substantial risks, even with repeated use," he says. But, he adds, better stop using it for sleep-inducing purposes. "...it is not a good idea to rely on a medication for sleep for an extended period. There are natural ways to improve sleep."

How long does Nyquil's drowsiness last? Nyquil's active ingredient, doxylamine, which has antihistamine and sedating effects, can lead to sleepiness. Nyquil can cause different degrees of sleepiness, depending on the individual lasting anywhere from 4 to 6 hours on average.

How long does Nyquil's drowsiness last? Nyquil's active ingredient, doxylamine, which has antihistamine and sedating effects, can lead to sleepiness. Nyquil can cause different degrees of sleepiness, depending on the individual lasting anywhere from 4 to 6 hours on average.

How long does NyQuil take to make you sleep? Most people will feel the effects of NyQuil, including drowsiness, within 30 minutes, but how it affects you may be different. After taking NyQuil, avoid driving, operating machinery, or other potentially dangerous activities until the effects of the medicine have worn off.