Melatonin vs Benadryl (diphenhydramine)

Melatonin vs Benadryl (diphenhydramine) – detailed comparison:


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


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

Currently, 1 in 3 American adults is not getting enough sleep on a regular basis, according to the Centers for Disease Control and Prevention.

In addition to improving sleep quality, melatonin is known to have an important role within the immune system as well it has anti-inflammatory action.


The usual recommended dose for adults is between 2-tenths of an mg and 5 mg 60 minutes before bedtime.

Side Effects and Precautions

Common side effects may include:

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

Rare side effects may include:

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

To be sure that melatonin is safe for you, tell your doctor if you have certain medical conditions, such as:

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

Drug Interactions

Some important drug interactions can occur when supplementing with this hormone, especially:

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

Pregnancy & Breastfeeding

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

In addition, it may pass into breast milk and may negatively affect the infant, hence, it is recommended to avoid it if you are breastfeeding an infant.


It is the brand name of a medication called diphenhydramine which belongs to a group of medications called antihistamines.

It is easily absorbed when taken by mouth and acts on cells in the brain, and, ultimately,  reduces the activity of histamine, a chemical messenger in the brain.

It was first approved by the US FDA in 1946 and is produced by Johnson & Johnson subsidiary McNeil Consumer Healthcare.


It is used to treat motion sickness, suppress coughs, and occasionally to treat mild forms of PD (Parkinson’s disease). Additionally, it is used to treat a runny nose, watery eyes, sneezing, rashes, hives, and other symptoms of allergies and the common cold.

Also, this antihistamine may decrease the time before you fall asleep, hence, it is used to temporarily relieve sleep problems.

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The usual recommended dose for adults is 25 to 50 mg at bedtime. Its effects continue for about 4 to 6 hours.

Important note – the medication shouldn’t be used in infants below 2 years since they don’t produce histamine in much quantity.

Store it at room temperature and keep it out of the reach of children.

Side Effects and Precautions of Diphenhydramine

Common side effects may include:

  • vertigo;
  • heartburn;
  • sun sensitivity;
  • dizziness;
  • tremors;
  • dry mouth;
  • early menstrual period;
  • a difficulty with coordination;
  • constipation or diarrhea;
  • tingling or numbness;
  • thickened chest mucus;
  • changes in mood;
  • loss of appetite;
  • stuffy nose.

Less common side effects may include:

  • low blood pressure;
  • swelling of the face or throat;
  • anemia;
  • rash or hives;
  • hallucinations;
  • tightness in the chest;
  • low blood platelets;
  • itchiness;
  • seizures;
  • heart palpitations;
  • confusion;
  • vision changes, such as – double vision or blurriness;
  • trouble passing urine;
  • irregular or rapid heartbeat.

To be sure that this antihistamine is safe for you, talk to your doctor before taking it, especially if you have any of these conditions:

  • overactive thyroid;
  • eye problems;
  • difficulty passing urine;
  • asthma;
  • chronic bronchitis;
  • heart disease;
  • hypertension;
  • seizures;
  • emphysema (a long-term lung disease).

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Drug Interactions

It may negatively interact with other medications, especially:

  • drugs for pain;
  • sleeping pills, sedatives, and tranquilizers;
  • meperidine (Demerol);
  • drugs for seizures;
  • erythromycin (Ery-Tab, Eryc, PCE);
  • pentamidine (Pentam, Nebupent);
  • barbiturates (a medication that acts as a central nervous system depressant);
  • drugs for mental illness, such as –  chlorpromazine (marketed under the trade names Largactil and Thorazine) or clozapine (Fazaclo ODT, Clozaril, Versacloz);
  • clarithromycin (Biaxin, Prevpac);
  • ondansetron (Zuplenz, Zofran);
  • drugs for anxiety;
  • moxifloxacin (Avelox);
  • drugs for arrhythmias, such as – amiodarone (Nexterone, Cordarone, Pacerone), procainamide, and quinidine (Nuedexta);
  • antidepressants, such as – fluoxetine (Sarafem, Prozac, Selfemra) and citalopram (Celexa);
  • droperidol (Inapsine);
  • gatifloxacin;
  • methadone (Methadose, Dolophine).


It is generally recommended to avoid drinking alcoholic beverages while taking this medication because it will increase the risk of side effects.

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Pregnancy & Breastfeeding

There are no well-done studies regarding the safe use of this medication during pregnancy, hence, ask your doctor before using this antihistamine if you are pregnant.

Also, it can pass into breast milk and may negatively affect the baby, hence, avoid this antihistamine if you are breastfeeding a baby.

Melatonin vs Benadryl (Diphenhydramine) – Which Is Better For Sleep?

Melatonin is a hormone that is secreted by the pineal gland in the brain. It is responsible for maintaining your body’s circadian rhythm.

Benadryl (active ingredient – diphenhydramine) is part of a class of medications called antihistamines. It works by blocking certain effects of histamine and is prescribed to relieve symptoms of the common cold and allergies.

According to studies, melatonin is safe and a great natural alternative to sleeping pills. However, if you take Benadryl nightly to fall asleep, you will build up a tolerance to the antihistamine, and it will lose its potency, hence, it won’t work anymore.

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