Sleep Disorders Treatment Using Diphenhydramine or Benadryl as a Sleep Aid Insomnia Medication Information About This Over-The-Counter Sleeping Pill By Brandon Peters, MD Brandon Peters, MD Facebook Twitter Brandon Peters, MD, is a board-certified neurologist and sleep medicine specialist. Learn about our editorial process Updated on April 07, 2022 Medically reviewed by Sanja Jelic, MD Medically reviewed by Sanja Jelic, MD Sanja Jelic, MD is board-certified in pulmonary disease, sleep medicine, critical care medicine, and internal medicine. She is an assistant professor and attending physician at Columbia University College of Physicians and Surgeons in New York, NY. Learn about our Medical Expert Board Print Table of Contents View All Table of Contents Uses How It Works Contraindications Side Effects Warnings and Interactions Frequently Asked Questions The over-the-counter medication diphenhydramine is found in many sleeping pills intended for insomnia treatment. It is the sleep-inducing element in many medications used as sleep aids. Since it does not require a prescription, many people who have acute insomnia use it to help initiate and maintain sleep. Due to the potential for side effects, especially among older people, other initial approaches for managing insomnia are often recommended. Brand New Images / Stone / Getty Images Uses Diphenhydramine has many potential uses. It causes sleepiness, and it is sometimes recommended for short-term treatment of insomnia or acute insomnia. By definition, this is insomnia that occurs for less than three months. It is one of the ingredients found in multiple sleep aids: Tylenol PM Advil PM Aleve PM ZzzQuil Benadryl It may help you get to sleep or stay asleep. However, it may cause sleepiness the day after taking it. Healthcare providers do not recommend the routine or chronic use of diphenhydramine to treat insomnia. In addition to its use as a sleep aid, diphenhydramine is often used to relieve allergies or treat allergic reactions, and it can be helpful in preventing motion sickness. It is also used to alleviate extrapyramidal symptoms, which may occur as a side effect of some medications. How It Works Diphenhydramine is part of a class of medications called antihistamines. It works at the level of neurotransmitters, which are the chemical messengers within the brain. It causes its sedative effects by allowing histamine, a neurotransmitter, to build up in the synapses, which are the spaces between nerve cells. Diphenhydramine specifically blocks the uptake of histamine into nearby cells. Diphenhydramine works both centrally within the brain as well as in peripheral nerve cells in other parts of the body. It also can suppress a cough, nausea, and uncontrolled movements called dyskinesis. Precautions and Contraindications Children younger than 2 years old should not use diphenhydramine. Additionally, caution should be used when this medication is used by children younger than 6 years old and by the elderly. Why Older People Should Avoid Diphenhydramine If you have increased intraocular pressure, such as in glaucoma, you should use caution with diphenhydramine. Other conditions may also require caution, including: AsthmaBowel or bladder obstructionChronic obstructive pulmonary diseaseHeart diseaseHigh blood pressureHyperthyroidismPeptic ulcer diseasePneumoniaProstate enlargement If you have these conditions, it's important to discuss your risk with your healthcare provider before starting to use the medication. If you are pregnant or breastfeeding, talk to your doctor before using any medication, supplement, or herb. Side Effects Some side effects that may commonly occur with diphenhydramine include: Delirium (confusion)Diminished coordination or cognitive functionDrowsinessDizzinessIncreased intraocular pressure (similar to glaucoma)HeadacheStomach discomfortThick lung secretionsDry mouth or noseHyperactivityConstipationDifficulty urinatingLow blood pressureBlurry or double visionRapid or irregular heart rateSensitivity to lightSweatingErectile dysfunction (impotence) Severe There are also risks of serious side effects. These occur more rarely. When using diphenhydramine, serious side effects may include: Anaphylaxis (severe allergic reaction including difficulty breathing)Low blood cell counts (agranulocytosis, anemia, thrombocytopenia, and leukopenia)Abnormal heart rhythmsSeizuresToxic psychosisAcute labyrinthitis (inner ear problems) Warnings and Interactions People who have certain conditions should use diphenhydramine with caution, or not at all. It is an over-the-counter medication, so the risks are thought to be slightly lower compared to prescription medications. Diphenhydramine has the potential to interact with some other drugs, especially those that affect the brain, so you may wish to review your medications with your healthcare provider or pharmacist before use. A Word From Verywell If you've been experiencing chronic insomnia that occurs at least three nights per week and lasts at least two weeks, talk to your healthcare provider. You might also consider the use of cognitive behavioral therapy for insomnia (CBTI) to resolve the condition instead of medication. You can use our Doctor Discussion Guide below to start a conversation with your healthcare provider about the most appropriate treatment approach. Frequently Asked Questions Is the sleep aid diphenhydramine the same as Benadryl? Yes. Diphenhydramine is the generic name for Benedryl, an antihistamine that causes drowsiness. Diphenhydramine works to promote sleep by altering neurotransmitter levels and causing sedative effects. How much Benadryl should I take to sleep? Typically two Benedryl tablets are taken to help with insomnia. Benadryl is commonly sold in 25 mg doses to treat an allergic reaction. For sleep, 50 mg of diphenhydramine is commonly recommended. Is is safe to use diphenhydramine for sleep every night? Diphenhydramine is a nonaddictive sleep aid. However, it is only recommended for short-term treatment of insomnia. Diphenhydramine is a type of drug known as anticholinergic. Regular use of anticholinergics is associated with an increased risk of dementia. Insomnia Doctor Discussion Guide Get our printable guide for your next healthcare provider's appointment to help you ask the right questions. Download PDF Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. 6 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Schroeck JL, Ford J, Conway EL, et al. Review of safety and efficacy of sleep medicines in older adults. Clin Ther. 2016;38(11):2340-2372. doi:10.1016/j.clinthera.2016.09.010 Albert SM, Roth T, Toscani M, Vitiello MV, Zee P. Sleep health and appropriate use of OTC sleep aids in older adults-recommendations of a Gerontological Society of America workgroup. Gerontologist. 2017;57(2):163–170. doi:10.1093/geront/gnv139 Sateia MJ, Buysse DJ, Krystal AD, Neubauer DN, Heald JL. Clinical practice guideline for the pharmacologic treatment of chronic insomnia in adults: An American Academy of Sleep Medicine clinical practice guideline. J Clin Sleep Med. 2017;13(2):307–349. doi:10.5664/jcsm.6470 Food and Drug Administration. Diphenhydramine hydrochloride injection, USP label. Farzam K, O'Rourke MC. Antihistamines. In: StatPearls. NIH Toxicology Data Network. Diphenhydramine. Additional Reading Epocrates. Diphenhydramine. By Brandon Peters, MD Brandon Peters, MD, is a board-certified neurologist and sleep medicine specialist. See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit