ZzzQuil vs Melatonin

ZzzQuil vs Melatonin – detailed comparison:


It is a very popular sleep supplement that is based on the original product called Nyquil.

This sleep supplement was designed for individuals who are healthy but are simply having trouble sleeping.

The main active ingredient in all ZzzQuil formulations is diphenhydramine, an antihistamine.

It works by binding to the H1 histamine receptor and functions as an inverse agonist.


It is typically used to induce sleep, to treat motion sickness and certain symptoms of Parkinson’s disease.

Also, the medication is used to treat sneezing, watery eyes, runny nose, itching, hives, skin rash, and other cold or allergy symptoms.


As a sleep aid, take this medication within half an hour before bedtime. Do not use it for children under 12 years of age.

Side Effects and Precautions

Common side effects may include:

  • day-time drowsiness after night-time use;
  • loss of coordination;
  • blurred vision;
  • drowsiness;
  • dry eyes;
  • dizziness;
  • upset stomach;
  • constipation;
  • dry nose, mouth, or throat.

Rare side effects may include:

  • uncontrollable movements of the tongue;
  • fluttering in the chest;
  • tightness in the neck or jaw;
  • pounding heartbeats;
  • a feeling like you might pass out;
  • difficult urination;
  • confusion;
  • little or no urinating.


Ask your healthcare provider if it is safe for you to take this drug if you have other medical conditions, particularly:

  • glaucoma;
  • a thyroid disorder;
  • blockage of the digestive tract;
  • if you take a potassium supplement;
  • bladder obstruction;
  • low blood pressure;
  • a colostomy or ileostomy;
  • heart disease;
  • a cough caused by emphysema, smoking, or chronic bronchitis;
  • kidney disease;
  • chronic obstructive pulmonary disease;
  • liver disease;
  • asthma;
  • a cough with mucus.


Drinking alcoholic beverages while taking this medication can substantially increase the risk of side effects.

Drug Interactions

It may negatively interact with other medications, especially:

  • Benadryl (diphenhydramine);
  • Adderall (amphetamine/dextroamphetamine);
  • gabapentin;
  • Advil (ibuprofen);
  • Klonopin (clonazepam);
  • Aleve (naproxen);
  • lisinopril;
  • amoxicillin;
  • metoprolol;
  • Control (phenylpropanolamine);
  • Prozac (fluoxetine);
  • zicam;
  • cyclobenzaprine;
  • phentermine;
  • ibuprofen;
  • Tylenol (acetaminophen);
  • Lexapro (escitalopram);
  • Tylenol PM (acetaminophen/diphenhydramine);
  • melatonin;
  • Zyrtec (cetirizine);
  • omeprazole;
  • Zoloft (sertraline);
  • oxycodone;
  • Xanax (alprazolam);
  • tramadol;
  • Vitamin D3 (cholecalciferol);
  • trazodone.

Pregnancy & Breastfeeding

Avoid using this medication during pregnancy, especially during the third trimester, since it may result in premature birth.

Also, avoid using this medication if you are breastfeeding a baby since this medication passes into breast milk and can negatively affect the infant, plus, it may decrease milk production.


It is a natural hormone that is secreted by your body’s pineal gland. It helps to maintain your “biological clock,” also referred to as the wake-sleep cycle or the circadian clock, an internal 24-hour “clock” that plays an important role in establishing when we wake up and when we fall asleep.


According to research, melatonin supplements may help sufferers with low melatonin levels (especially people with schizophrenia and people 65 years or older) and people with disrupted circadian rhythms (such as – individuals who work the night shift or people with jet lag) to sleep better.

In the present day, 1 in 3 American adults is not getting sufficient sleep on a regular basis, according to the CDC.

In addition to improving sleep quality, this supplement is known to have an essential role in the immune system as well it has a potent anti-inflammatory action.


The usual recommended dosage for adults is between 2-tenths of an mg and 5 mg one hour before bedtime.

READ MORE: Dayquil vs Nyquil

Side Effects and Precautions

Common side effects may include:

  • dizziness;
  • nausea;
  • diarrhea;
  • increased risk for seizures;
  • headaches.

Less common side effects may include:

  • loss of appetite;
  • stomach pain;
  • vivid dreams;
  • daytime drowsiness;
  • feeling depressed or anxious;
  • joint or back pain;
  • confusion;
  • blood pressure changes;
  • weakness.

To be sure that this supplement is safe for you, tell your healthcare provider if you have certain medical conditions, such as:

  • high or low blood pressure;
  • type 2 diabetes;
  • epilepsy or other seizure disorder;
  • an autoimmune disease;
  • using any medicines to prevent organ transplant rejection;
  • depression;
  • a bleeding or blood clotting disorder;
  • using other sedatives;
  • taking a blood thinner, like warfarin.

READ MORE: Theraflu vs Alka Seltzer

Drug Interactions

It may negatively interact with other medications, especially:

  • dilantin;
  • caffeine;
  • blood-thinner medications (anticoagulants), like – heparin, warfarin, or aspirin;
  • fluvoxamine (Luvox);
  • medications for diabetes;
  • nifedipine;
  • sedative-type medications.

Pregnancy & Breastfeeding

It may pass into breast milk and negatively affect the infant; therefore, it is recommended to avoid this supplement if you are breastfeeding an infant.

Most dietary supplements like this one have not been well-studied in pregnant women; hence, it is recommended to contact your doctor before using this supplement if you are pregnant or plan to fall pregnant.

READ MORE: Gammagard vs Gamunex

Bottom Line – ZzzQuil vs Melatonin

ZzzQuil (active ingredient – diphenhydramine) is a medication that is used to treat motion sickness, induce sleep, and treat allergy symptoms. The main and only active ingredient in this medication is also the main ingredient in almost every other over-the-counter sleep medication, and even nighttime pain reliever.

Melatonin is an over-the-counter dietary supplement that may help sufferers with low melatonin levels and people with disrupted circadian rhythms to sleep better.

One review of 15 studies involving 284 subjects concluded that people who took melatonin supplements before bed fell asleep 3.9 minutes faster on average and slept 13 minutes longer.

Regarding ZzzQuil, a study that was presented during an annual meeting of the American Academy of Sleep Medicine and the Sleep Research Society in 2016, showed that OTC sleep medicines help people suffering from occasional sleep difficulties fall asleep in less than twenty minutes and improve their reported quality of sleep.

Basically, ZzzQuil may put you to sleep faster than melatonin, but at the end of the day, is it the best choice?

Most doctors don’t recommend ZzzQuil for sleep difficulties due to the fact that so many people build a tolerance to diphenhydramine. In addition, it doesn’t really fix the underlying problem…it just masks the problem.

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