Benadryl is a brand of various
antihistamine
Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides ...
medications used to stop
allergies
Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include Allergic rhinitis, hay fever, Food allergy, food al ...
, whose content varies in different countries, but which includes some combination of
diphenhydramine
Diphenhydramine, sold under the brand name Benadryl among others, is an antihistamine and sedative. Although generally considered sedating, diphenhydramine can cause paradoxical central nervous system stimulation in some individuals, particula ...
,
acrivastine, or
cetirizine.
It is sold by
Kenvue and is used to relieve allergy symptoms such as sneezing, itching, runny nose,
rash
A rash is a change of the skin that affects its color, appearance, or texture.
A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracke ...
, and
hives
Hives, also known as urticaria, is a kind of skin rash with red or flesh-colored, raised, itchy bumps. Hives may burn or sting. The patches of rash may appear on different body parts, with variable duration from minutes to days, and typically ...
.
Some forms of Benadryl are to be taken orally, while some creams and gels are to be applied to the skin.
Common side effects of the drug include
drowsiness,
dizziness
Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to Balance disorder, disequilibrium or a non-specific feeling, such as giddiness or foolishness.
Dizziness is a ...
, dry mouth and throat, confusion, and
blurred vision.
In the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
and
Canada
Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...
, the active ingredient is
diphenhydramine
Diphenhydramine, sold under the brand name Benadryl among others, is an antihistamine and sedative. Although generally considered sedating, diphenhydramine can cause paradoxical central nervous system stimulation in some individuals, particula ...
. In the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...
, the active ingredients of Benadryl are the second-generation antihistamines
acrivastine or
cetirizine. Benadryl is also sold as a
cough medicine in
Australia
Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...
,
India
India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...
and
New Zealand
New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...
containing
diphenhydramine
Diphenhydramine, sold under the brand name Benadryl among others, is an antihistamine and sedative. Although generally considered sedating, diphenhydramine can cause paradoxical central nervous system stimulation in some individuals, particula ...
, as well as the
antitussive dextromethorphan
Dextromethorphan, sold under the brand name Robitussin among others, is a cough suppressant used in many cough and Common cold, cold medicines. In 2022, the US Food and Drug Administration (FDA) approved the combination dextromethorphan/bupropi ...
or the
expectorant guaifenesin.
Types of Benadryl
There are many different forms of Benadryl found in different countries. In the United States and Canada, there are several versions of Benadryl for allergies, some to be taken orally and some as a
topical analgesic. In Australia, New Zealand and
India
India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...
, Benadryl is known as a cough liquid.
Benadryl Allergy
Benadryl Allergy is the name of a Benadryl product found in the United States and Canada. It is an antihistamine drug used to relieve allergies. Its active ingredient is
diphenhydramine
Diphenhydramine, sold under the brand name Benadryl among others, is an antihistamine and sedative. Although generally considered sedating, diphenhydramine can cause paradoxical central nervous system stimulation in some individuals, particula ...
, a
first-generation antihistamine. It is known to be sedative, making drowsiness a common side effect. It is an oral drug to be taken by mouth, to relieve symptoms of allergy,
hay fever
Allergic rhinitis, of which the seasonal type is called hay fever, is a type of rhinitis, inflammation in the nose that occurs when the immune system overreacts to allergens in the air. It is classified as a Allergy, type I hypersensitivity re ...
and the
common cold
The common cold, or the cold, is a virus, viral infectious disease of the upper respiratory tract that primarily affects the Respiratory epithelium, respiratory mucosa of the human nose, nose, throat, Paranasal sinuses, sinuses, and larynx. ...
.
It can also be used to relieve allergies such as itching, sneezing, runny nose, rash and hives.
Benadryl Allergy for Children is also available. It comes in liquid form and can be used to provide fast and effective relief for allergies such as sneezing, itchy, runny nose, itchy eyes and hives.
Benadryl Allergy is widely used as a sleep aid among adults. While it is not marketed as an
over-the-counter (OTC) sleeping aid, most versions of Benadryl contain diphenhydramine, a drug with
sedative
A sedative or tranquilliser is a substance that induces sedation by reducing irritability or Psychomotor agitation, excitement. They are central nervous system (CNS) Depressant, depressants and interact with brain activity, causing its decelera ...
properties. Diphenhydramine (Benadryl) has also been used by parents to help improve their infant's sleep habits. However,
this has been met by criticism on whether it is appropriate to do so.
Benadryl Allergy Relief
In the United Kingdom, Benadryl can be found as Benadryl Allergy Relief. The main ingredient in this medication is acrivastine. Acrivastine is a non-drowsy antihistamine used to relieve allergies. It can treat hay fever, hives, insect bites and stings,
conjunctivitis
Conjunctivitis, also known as pink eye or Madras eye, is inflammation of the conjunctiva, the thin, clear layer that covers the white surface of the eye and the inner eyelid. It makes the eye appear pink or reddish. Pain, burning, scratchiness ...
and
eczema
Dermatitis is a term used for different types of skin inflammation, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened ...
.
Benadryl Allergy Relief contains 8 mg of acrivastine in each capsule. It is to be taken orally.
Benadryl Allergy Relief Plus Decongestant can also be found in the United Kingdom. It is used to relieve
sinus, stuffy and runny nose, itchy eyes and sneezing.
This version contains acrivastine and
pseudoephedrine as its active ingredients. Pseudoephedrine is a
decongestant used to relieve a
nasal congestion.
Benadryl Allergy Relief Plus Decongestant contains 8 mg of acrivastine and 60 mg of pseudoephedrine per capsule, and it is to be taken orally.
Benadryl Topical
Benadryl can also be found in a topical form including gels and creams. Benadryl Itch Stopping Cream is a topical cream used to provide temporary itch relief for allergies, hives or even some insect bites. It can be found in the United States and Canada. This topical medication contains 2% of diphenhydramine hydrochloride and 1% of zinc acetate. This medication is intended for topical use only and not to be ingested.
Benadryl Cough Syrup

Benadryl in Australia and New Zealand comes in the form of a cough syrup. It is not to be confused with Benadryl for allergies. There are several forms of cough syrup available in the market for different types of coughs such as dry, tickly cough, chesty coughs and coughs with nasal congestion. Cough liquids for children are also available.
Benadryl Chesty Forte is used to relieve heavy chesty coughs and chest congestion. The main ingredients found are
guaifenesin and bromhexine hydrochloride. It is to be taken orally to provide relief from cough and congested chests due to the common cold. Benadryl Dry, Tickly Cough Liquid is a cough medicine found in Australia. It is used to temporarily relieve irritating coughs.
Pholcodine is the main ingredient found in this cough liquid. This medication is to be taken orally and may cause drowsiness.
In India, Benadryl can also be found in the form of a cough liquid and also cough lozenges. Benadryl Cough Syrup contains diphenhydramine,
ammonium chloride
Ammonium chloride is an inorganic chemical compound with the chemical formula , also written as . It is an ammonium salt of hydrogen chloride. It consists of ammonium cations and chloride anions . It is a white crystalline salt (chemistry), sal ...
and citrate as its main ingredients. It is used to relieve cough and cold, and also soothes the throat.
Adverse effects
A common side effect of taking Benadryl containing diphenhydramine is drowsiness.
Other common side effects can include dry mouth and throat. Symptoms such as confusion and blurred vision can also occur. Other side effects of taking Benadryl include
headache
A headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of Depression (mood), depression in those with severe ...
and dizziness.
Diphenhydramine is a
first-generation antihistamine and an
anticholinergic drug. Anticholinergic drugs block the action of
acetylcholine
Acetylcholine (ACh) is an organic compound that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Par ...
, a
neurotransmitter
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a Chemical synapse, synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell.
Neurotra ...
in the
central nervous system
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...
.
Studies propose that long-term use of anticholinergic drugs is associated with an increased risk for
dementia
Dementia is a syndrome associated with many neurodegenerative diseases, characterized by a general decline in cognitive abilities that affects a person's ability to perform activities of daily living, everyday activities. This typically invo ...
among older people.
Long-term use of Benadryl can also lead to
constipation
Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The Human feces, stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the ...
and
confusion
In psychology, confusion is the quality or emotional state of being bewildered or unclear. The term "acute mental confusion" .
Interactions
Benadryl containing diphenhydramine can interact with
alcohol
Alcohol may refer to:
Common uses
* Alcohol (chemistry), a class of compounds
* Ethanol, one of several alcohols, commonly known as alcohol in everyday life
** Alcohol (drug), intoxicant found in alcoholic beverages
** Alcoholic beverage, an alco ...
as both are central nervous system (CNS)
depressant
Depressants, also known as central nervous system depressants, or colloquially known as "downers", are drugs that lower neurotransmission levels, decrease the electrical activity of brain cells, or reduce arousal or stimulation in various ...
s. Side effects such as drowsiness and dizziness may be enhanced when taking alcohol with diphenhydramine. Mixing diphenhydramine with alcohol can also increase the chances of losing consciousness due to sedation.
This combination can also lead to impaired motor skills and decreased
alertness. Driving, operating machinery or any other activities that require full concentration and consciousness are not recommended as these effects persist.
Benadryl may interact with other medications such as
anti-depressants, sleeping pills, muscle relaxants and other antihistamines.
It is important to check with a professional before taking Benadryl with any other medications,
vitamin
Vitamins are Organic compound, organic molecules (or a set of closely related molecules called vitamer, vitamers) that are essential to an organism in small quantities for proper metabolism, metabolic function. Nutrient#Essential nutrients, ...
s and
herbal products.
History
In 1943, diphenhydramine was discovered by chemist
George Rieveschl
George Rieveschl (January 9, 1916 – September 27, 2007) was an American chemist and professor. He was the inventor of the popular antihistamine diphenhydramine (Benadryl), which he first made while searching for potential muscle relaxant drugs ...
and one of his students, Fred Huber, while they were conducting research into
muscle relaxant
A muscle relaxant is a drug that affects skeletal muscle function and decreases the muscle tone. It may be used to alleviate symptoms such as muscle spasms, pain, and hyperreflexia. The term "muscle relaxant" is used to refer to two major therapeu ...
s at the
University of Cincinnati
The University of Cincinnati (UC or Cincinnati, informally Cincy) is a public university, public research university in Cincinnati, Ohio, United States. It was founded in 1819 and had an enrollment of over 53,000 students in 2024, making it the ...
.
Huber first synthesized diphenhydramine. Rieveschl then worked with
Parke-Davis to test the compound, and the company licensed the patent from him.
In 1946, Benadryl was approved by the
Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...
(FDA) for prescription use. In 1982 it was approved as an over-the-counter medication.
Before 2007, Benadryl was marketed by
Pfizer
Pfizer Inc. ( ) is an American Multinational corporation, multinational Pharmaceutical industry, pharmaceutical and biotechnology corporation headquartered at The Spiral (New York City), The Spiral in Manhattan, New York City. Founded in 184 ...
Consumer Healthcare (originally
Warner–Lambert).
Recalls
On 15 January 2010,
McNeil Consumer Healthcare, a subsidiary of
Johnson & Johnson
Johnson & Johnson (J&J) is an American multinational pharmaceutical, biotechnology, and medical technologies corporation headquartered in New Brunswick, New Jersey, and publicly traded on the New York Stock Exchange. Its common stock is a c ...
, recalled five lots of Benadryl due to the presence of an unusual odor linked to the chemical
2,4,6-tribromoanisole.
In April 2010, over four million packs of Benadryl Children Allergy tablets were recalled after it was revealed that they might contain a higher concentration of active ingredients than specified on the label, as well as inactive ingredients that had not met internal testing requirements.
Benadryl topical packaging change
In 2010, after the U.S. Food and Drug Administration (FDA) reported over one hundred cases of mistaken ingestion by mouth, the packaging of Benadryl Itch Stopping Gel was redesigned to include a new warning ("for skin use only"), and a sticker was added as an additional precaution.
Society and culture
Diphenhydramine has a common side effect of drowsiness or sleepiness.
Because of these sedative properties, Benadryl is often used as a sleep aid in people with
insomnia
Insomnia, also known as sleeplessness, is a sleep disorder where people have difficulty sleeping. They may have difficulty falling asleep, or staying asleep for as long as desired. Insomnia is typically followed by daytime sleepiness, low ene ...
. A study published in the ''
American Journal of Geriatric Psychiatry'' discovered that approximately one in three adults between the ages of 65 and 80 occasionally use over-the-counter drugs like Benadryl to help with sleep.
In 2017,
American Academy of Sleep Medicine
The American Academy of Sleep Medicine (AASM) is a United States professional society for the medical subspecialty of sleep medicine which includes disorders of circadian rhythms. It was established in 1975.
The organization's functions includ ...
discouraged the use of over-the-counter antihistamines as a sleep aid in treating chronic insomnia.
The usage of antihistamines as a sleep aid could cause sleepiness during the day, grogginess and falls.
Recreational usage and the 'Benadryl challenge'
In May 2020, the Cook Children's Medical Center in Fort Worth, TX reported that 3 teenagers had been hospitalized as a result of diphenhydramine overdose. They claimed that the teenagers had gotten information on how to abuse Benadryl from the social media app
TikTok
TikTok, known in mainland China and Hong Kong as Douyin (), is a social media and Short-form content, short-form online video platform owned by Chinese Internet company ByteDance. It hosts user-submitted videos, which may range in duration f ...
. That August, an Oklahoma teen reportedly died from a Benadryl overdose. After a later-deleted Facebook post by the teen's family member claimed that the death was the result of a "
Benadryl challenge," news outlets reported on the dangers of the supposed social media trend. This prompted the FDA to release a statement on the dangers of high doses of diphenhydramine.
Availability
Benadryl is available as an over-the-counter (OTC) drug in most countries. Benadryl can be found in several countries including the United States, Canada, United Kingdom, Australia, New Zealand, India, Indonesia and the Philippines.
Benadryl comes in oral tablets and oral liquid to be taken by mouth.
Some types of Benadryl such as Benadryl Itch Stopping Cream and gels are meant to be applied to the skin, not to be ingested.
References
External links
*
{{Johnson & Johnson
Drugs developed by Johnson & Johnson
H1 receptor antagonists
Products introduced in 1946
Antihistamines