Benadryl dosage, forms, and strengths

Benadryl (diphenhydramine) is an over-the-counter medication that temporarily relieves allergy symptoms caused by the neurotransmitter histamine. Benadryl reduces symptoms such as runny nose, watery eyes, and itching in addition to causing drowsiness. The standard dosage of Benadryl is 25 to 50 mg (one to two tablets or capsules)every four to six hours with or without food. Children between the ages of 6 and 11 can be given Benadryl at a maximum dose of 25 mg (one tablet or capsule) every four to six hours. 

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Benadryl dosage forms and strengths

Benadryl tablets and gel capsules contain 25 mg of diphenhydramine hydrochloride and are typically taken by adults and children 6 years and older. Benadryl Allergy Plus Congestion, however, also contains 10 mg of phenylephrine hydrochloride, a nasal decongestant. Benadryl Allergy Plus Congestion should not be given to children younger than 12 unless directed by a physician.

• Benadryl Allergy Ultratab Tablets: 25 mg diphenhydramine per tablet

• Benadryl Allergy Dye-Free Liqui-Gels: 25 mg diphenhydramine per gel capsule

• Benadryl Allergy Plus Congestion: 25 mg diphenhydramine/10 mg phenylephrine per tablet

Standard Benadryl Dosing

Adults

• Standard Benadryl dosage for adults: One to two tablets/capsules (25-50 mg) every four to six hours.

• Maximum Benadryl dosage for adults: Two tablets/capsules (50 mg) every four hours to a maximum of 12 tablets (300 mg) in 24 hours.

Children

Benadryl dosages may be based on age or weight in children. Children’s Benadryl Allergy is more suitable for children between the ages of 6 and 11. Containing half the dose of diphenhydramine (12.5 mg) as Benadryl Allergy, Children’s Benadryl Allergy is sold in child-friendly liquid and chewable tablet formats.

• Children’s Benadryl dosage for children ages 2 to 5: Do not give unless directed by a physician.

• Children’s Benadryl dosage for children ages 6 to 11: One to two chewable tablets or 5 to 10 mL every four to six hours to a maximum of 12 tablets or 60 mL in 24 hours.

• Children’s Benadryl dosage for children ages 12 and older: Two to four chewable tablets or 10 to 20 mL every four to six hours to a maximum of 24 tablets or 120 mL in 24 hours.

Benadryl dosage for children

Benadryl dosages may be based on age or weight in children. Children’s Benadryl Allergy is more suitable for children between the ages of 6 and 11. Containing half the dose of diphenhydramine (12.5 mg) as Benadryl Allergy, Children’s Benadryl Allergy is sold in child-friendly liquid and chewable tablet formats.

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Can you give the adult formulation of Benadryl to children?

Benadryl (the adult formulation: 25 mg) may be given to children between the ages of 6 and 11, but should not be given to children younger than 6. Although Benadryl Allergy may be used to relieve insomnia in children 12 or older, it should not be used as a sleep aid in children younger than 12.

• Standard Benadryl dosage for children younger than 6: Do not give unless directed by a physician.

• Standard Benadryl dosage for children ages 6 to 11: One tablet/capsule (25 mg) every four to six hours.

• Maximum Benadryl dosage for children ages 6 to 11: One tablet/capsule (25 mg) every four hours to a maximum of six tablets (150 mg) in 24 hours.

Note: Children between the ages of 6 and 11 should be not given Benadryl Allergy Plus Congestion except under the direction of a pediatrician. 

Benadryl dosage for specific indications

Benadryl relieves symptoms caused by allergies, hay fever, or the common cold including runny nose, congestion, sinus pressure, sneezing, rash, watery or itchy eyes, and itchy nose. Benadryl is also indicated to relieve itchy skin (pruritus) caused by histamine release due to an allergic reaction (contact dermatitis), hives (urticaria), or insect bites. Due to its effect on histamine receptors in the body, Benadryl is also useful in the treatment of motion sickness and insomnia. The dosage for these indications can vary. The table below provides guidelines on the appropriate dose depending on the intended use.

Benadryl dosage for pets

Benadryl is not approved for use in pets, but your veterinarian may recommend off-label use in your pet for some indications.

RELATED: How to treat allergies in cats and dogs

How to take Benadryl

For healthy adults and children 12 or older, take one to two tablets or capsules by mouth every four to six hours or as directed by a healthcare provider. Benadryl can be taken with or without food.

• Follow the instructions on the medicine label if you are using this medicine without a prescription.

• If you are using this medicine with a prescription, the prescribing doctor will tell you how much medicine to use. Do not use more than directed.

• Swallow the tablet or gel capsule whole. Do not crush, break, or chew it.

When taking or administering Benadryl, you may want to consider the following safety and effectiveness tips:

• Always check the expiration date. If the medicine has passed its expiration date, dispose of it safely and purchase a new box.

• Store Benadryl at room temperature (68-77F)

• Check all other medications that you or your child are taking to make sure they do not also contain diphenhydramine or phenylephrine. Both are commonly found in combination cold, flu, or allergy medications. Pay particular attention to topical itch medications that may contain diphenhydramine. These drugs—including topical diphenhydramine—should never be used with Benadryl.

• Do not take Benadryl with alcohol or sedatives. This can cause over-sedation.

• People who have glaucoma, breathing problems due to emphysema or chronic bronchitis, or difficulty urinating due to an enlarged prostate should talk to a doctor before taking Benadryl.

• Women who are pregnant or breastfeeding should seek medical advice before taking Benadryl.

• Although Benadryl is approved for children 6 years or older, Benadryl Allergy should not be used as a sleep aid in children younger than 12. 

• For motion sickness, take Benadryl 30 minutes before traveling or exposure to motion. If you are going on a long trip, take the next doses every six to eight hours.

• For each dose, record the time in a diary or schedule to ensure that the next dose is not given too early.

• Benadryl is a sedative, so do not operate machinery or drive if you feel tired, woozy, or unfocused. It’s a good idea to remove obstacles and hazards in the home before taking diphenhydramine.

Benadryl dosage FAQs

How quickly will Benadryl work, and how long will it last?

Taken as directed, Benadryl Allergy usually starts working 30 minutes after being swallowed and reaches peak levels in the body in approximately two hours. At the recommended dosage, the effects of Benadryl should last four to six hours, but this will vary. As a general rule, the amount of time Benadryl stays in the system increases with age. 

Healthcare professionals measure how long a drug stays in the body by half-life, which is the time it takes for the body to eliminate half the amount of a drug in the body. The half-life of diphenhydramine in children is four to seven hours (five hours average). For adults, the half-life is seven to 12 hours (nine hours average). For seniors, the half-life ranges from nine to 18 hours (average: 13.5 hours).

What happens if I miss a dose of Benadryl?

There is no problem missing a dose of Benadryl. Take the missed dose at any time. The dosing schedule will reset, so wait at least four hours before taking the next dose. Do not take extra medicine to make up for a missed dose.

How do I stop taking Benadryl?

Benadryl can be used regularly to treat allergic reactions or motion sickness. It should be used only occasionally as a sleep aid. Diphenhydramine is sometimes abused. Chronic use of Benadryl, especially to relieve anxiety or sleeplessness, may result in dependence and produce withdrawal symptoms if Benadryl is rapidly discontinued. High doses of Benadryl can cause serious heart problems, seizures, coma, and death. Before discontinuing Benadryl after long-term regular use, talk to a healthcare provider about tapering the Benadryl dose or using alternative medications or therapies for reducing anxiety or treating insomnia.

You should discontinue Benadryl and consult a healthcare provider if you experience excessive nervousness, sleepiness, allergic reactions, or if symptoms do not improve after seven days.

What can be used instead of Benadryl Allergy?

Healthcare professionals usually discourage the routine use of first-generation antihistamines such as diphenhydramine, the active ingredient in Benadryl. Second-generation antihistamines are equally as effective as diphenhydramine without causing as much sedation or drowsiness. Instead of Benadryl Allergy, you can choose several over-the-counter second-generation antihistamines for daily use such as Claritin (loratadine), Alavert (loratadine), Allegra (fexofenadine), Zyrtec (cetirizine), and Xyzal (levocetirizine). 

What interacts with Benadryl?

Foods do not interfere with the absorption or effectiveness of Benadryl. 

Several OTC and prescription drugs can interact with Benadryl, and some may reduce Benadryl’s effectiveness. Drugs that depress or slow down the central nervous system such as tranquilizers, alcohol, or sedatives may enhance Benadryl side effects such as drowsiness, dizziness, sedation, dry mouth, and blurred vision. Always talk to a healthcare provider before combining Benadryl Allergy with central nervous system depressants or other medications.

Benadryl Allergy Plus Congestion also contains phenylephrine, a stimulant. When taken with monoamine oxidase inhibitors (MAOIs), a family of drugs that includes certain types of antidepressants, antibiotics, and Parkinson’s medications, phenylephrine can cause a dangerous and potentially life-threatening rise in blood pressure. Consult with your doctor, pharmacist, or other healthcare provider if you think a medication you’re taking might be an MAO inhibitor.

Sources: 

• Benadryl dosing guide, Johnson & Johnson 

• Benadryl Allergy Ultratab Tablets, Johnson & Johnson 

• Benadryl Allergy Dye-Free Liqui-Gels, Johnson & Johnson 

• Benadryl Allergy Plus Congestion, Johnson & Johnson 

• Diphenhydramine compound summary, National Library of Medicine (2025)

• Diphenhydramine, StatPearls, National Library of Medicine (2023)

• Diphenhydramine for animals, VCA Hospitals

• Chronic diphenhydramine abuse and withdrawal, Neurol Clin Pract (2017)

• The pharmacologic management of motion sickness, U.S. Pharmacist (2015)

• FDA warns about serious problems with high doses of the allergy medicine diphenhydramine, FDA (2020)