Does DayQuil Keep You Awake? Here’s What You Need to Know

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When you’re suffering from cold and flu symptoms like cough, congestion, headache and fever, getting a good night’s sleep can seem impossible. Many people turn to over-the-counter medications like DayQuil to get relief from their symptoms. But some find that even after taking DayQuil, they still can’t seem to fall asleep.

So does DayQuil actually keep you awake? Here we’ll explore the ingredients in DayQuil, reasons it may disrupt sleep, and tips for taking DayQuil while still getting some rest.

What is DayQuil?

DayQuil is an over-the-counter medication manufactured by Vicks and marketed specifically for relief of daytime cold and flu symptoms. It comes in both liquid and caplet formulations.

The active ingredients in DayQuil include acetaminophen for pain and fever reduction, dextromethorphan as a cough suppressant, phenylephrine as a nasal decongestant, and doxylamine succinate as an antihistamine. The antihistamine doxylamine succinate is responsible for many of DayQuil’s side effects like drowsiness.

When used as directed, DayQuil alleviates symptoms like:

  • Headache
  • Fever
  • Cough
  • Sore throat
  • Nasal congestion
  • Minor aches and pains

Because it contains no ingredients intended to make you sleep, DayQuil is marketed as a non-drowsy cold medicine that provides relief of major symptoms without making you sleepy.

DayQuil Ingredients That Cause Drowsiness

While DayQuil itself does not contain sleep-aids, some of the ingredients like doxylamine succinate can still cause drowsiness.

Doxylamine succinate is an antihistamine that blocks the effects of histamine in your body. Histamine promotes your immune response and contributes to symptoms like runny nose, watery eyes, and sneezing. Blocking histamine reduces these effects so you can get congestion relief.

Side effects of antihistamines like doxylamine succinate include:

  • Drowsiness
  • Dizziness
  • Headaches
  • Dry mouth
  • Nausea

So even though DayQuil doesn’t contain ingredients like diphenhydramine (found in nighttime cold medicines like NyQuil), its antihistamine can still make you sleepy.

Dextromethorphan also causes drowsiness in some people, especially at higher doses. It may induce a sedated feeling as it suppresses the urge to cough.

Why DayQuil May Disrupt Sleep

Even if you don’t feel super drowsy after taking DayQuil, it can still disrupt your sleep in other ways. Here are some reasons you may toss and turn even if DayQuil hasn’t knocked you out:

1. Side effects like insomnia: While many experience drowsiness from DayQuil, others report side effects like insomnia and sleeplessness instead. The antihistamine doxylamine succinate may overstimulate the central nervous system and make it hard to fall asleep for some people.

2. Nighttime waking: DayQuil only provides temporary relief. Its effects start fading 2-6 hours after taking it. Congestion, cough, and other symptoms returning in the middle of the night can wake you up.

3. Masking symptoms: During the day, DayQuil reduces irritating symptoms like cough and nasal congestion. But this masking effect wears off during the night. The return of symptoms disrupts sleep.

4. Restlessness: Doxylamine succinate can cause restlessness or jitteriness in some people. An inability to get comfortable at night leads to tossing, turning, and poor sleep.

5. Dehydration: DayQuil contains phenylephrine as a decongestant. Phenylephrine constricts blood vessels in the nasal passages, reducing swelling. But it can also be dehydrating. Dehydration may cause you to wake up thirsty.

6. Fever breaking: DayQuil lowers body temperature from a fever during the day. When the fever breaks at night, drenching sweats can interrupt sleep.

So even if DayQuil itself doesn’t make you drowsy, its side effects and the returning symptoms of illness can still interfere with your sleep.

Tips for Preventing DayQuil from Keeping You Awake

If you need DayQuil for cold relief during the day but don’t want it to disrupt your sleep, here are some tips:

Take it early: Take DayQuil as early in the day as possible, at least 8 hours before bedtime. This prevents active ingredients from still being in your system at night.

Try non-drowsy formulas: Look for DayQuil products labeled “non-drowsy.” For example, DayQuil Severe doesn’t contain the antihistamine doxylamine that causes drowsiness.

Lower your dose: Stick to recommended DayQuil dosages. Taking more than directed can increase side effects like insomnia, restless legs, etc.

Stay hydrated: Drink plenty of fluids during and after taking DayQuil to prevent dehydration and nighttime thirst.

Use nighttime cold meds: Take NyQuil at night for symptom relief instead of DayQuil. It contains the sleep-aid doxylamine succinate to both treat symptoms and promote sleep.

Try other OTC nighttime sleep aids: Consider diphenhydramine (Benadryl) or doxylamine succinate (Unisom) products to fall asleep if cold symptoms are keeping you up.

Use humidifiers and nasal strips: Use humidifiers and breath strips to relieve congestion and coughing without medications.

Create a good sleep environment: Sleep in a cool, comfortable room away from noise and light. Use eye masks, ear plugs, and white noise if needed.

Ask your doctor: If your cough, congestion, or pain is so severe it routinely disrupts sleep even with DayQuil, ask your doctor about prescription symptom relief.

With some adjustments to when and how much DayQuil you take, plus good sleep hygiene, you can continue taking it for daytime cold relief without losing sleep at night.

Does DayQuil Keep You Awake? The Bottom Line

To summarize, while DayQuil itself doesn’t contain sleep-inducing ingredients, some active components like doxylamine succinate can cause drowsiness as a side effect. However, DayQuil may also disrupt sleep in other ways like causing insomnia, allowing symptoms to rebound at night, and contributing to dehydration.

There is no definitive answer on whether DayQuil will make you sleepy or keep you awake. It varies based on your individual response. Taking DayQuil as directed during the day along with other nighttime symptom relievers is your best bet for treating cold and flu symptoms around the clock without disrupting your sleep.

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