How much Benadryl can I take? What is too much?
The maximum safe Benadryl (diphenhydramine) dose for adults is 50 to 100 mg for a single dose with a daily maximum of 300 mg in 24 hours. However, your safe Benadryl dose depends on:
- Medical conditions (kidney/liver disease, glaucoma, enlarged prostate)
- Age (seniors need lower doses)
- Previous tolerance to diphenhydramine
- Other medications (especially sedatives, alcohol)
- Weight and body size
- What condition you are using diphenhydramine for
- The diphenhydramine salt that is used (there are two salts available in the United States, diphenhydramine hydrochloride and diphenhydramine citrate).
⚠️ WARNING: Taking too much diphenhydramine can be fatal. never exceed the recommended dosages.
What is Benadryl (diphenhydramine)?
Benadryl is a brand) name for diphenhydramine hydrochloride, a sedating antihistamine used to treat allergies, sleep problems, and motion sickness. The recommended dosage of Benadryl by condition is as follows.
Allergic rhinitis:
- 25 to 50 mg every 4 to 6 hours as needed.
- Maximum: 300 mg per day.
Cold symptoms, itch (pruritus), or hives (urticaria):
- 25mg to 50 mg every 4 to 6 hours as needed.
- Maximum: 300 mg per day.
Sleep Aid (insomnia):
- 50 mg once at bedtime only
- Maximum dose: 50 mg per day.
- Important: Not for long-term sleep use.
Motion sickness prevention:
- 25 to 50 mg 3-4 times daily as needed.
- Maximum: 300 mg per day
- Timing: Take 30 minutes before travel.
Dosages for children vary depending on age or body weight: please consult with a pediatrician. See the diphenhydramine dosage guide for more detailed information.
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Benadryl overdose signs - seek emergency help
Call 911 if you experience:
- Severe drowsiness or inability to wake up
- Rapid heartbeat or heart palpitations
- Seizures or tremors
- Hallucinations or confusion
- Difficulty breathing
- Loss of consciousness.
Who should avoid Benadryl?
Don't take Benadryl (diphenhydramine) if you have:
- Narrow-angle glaucoma
- Enlarged prostate (benign prostatic hyperplasia)
- Severe kidney or liver disease
- Bladder obstruction
- Known allergy to antihistamines.
Frequently Asked Questions
Can you take Benadryl every day?
For chronic conditions, consult your doctor. Long-term daily use isn't recommended.
What happens if you take too much Benadryl?
Overdose can cause dangerous heart rhythms, seizures, coma, and death. Call your healthcare provider if you take too much Benadryl, but seek urgent medical attention if you develop any of these symptoms.
Can you take Benadryl with other allergy medications?
Don't combine Benadryl with other antihistamines without medical supervision.
Is generic diphenhydramine the same as Benadryl?
Yes, generic versions contain the same active ingredient with identical effects, although the dosage may be different depending on the salt used.
References
- Benadryl. Drugs.com https://www.drugs.com/benadryl.html
- Diphenhydramine. Drugs.com https://www.drugs.com/diphenhydramine.html
Read next
What cold medicine can you take with diabetes?
If you have diabetes and you catch a cold or flu, there are over-the-counter (OTC) medicines that are safe for you to take to help alleviate your symptoms. Check out our suggestions for pain and fever relievers, cough and congestion medications and more.
Remember to look for cold and flu medicines that are less likely to affect your blood sugar (glucose) levels, including sugar-free and alcohol-free options, or worsen any diabetes complications you may have.
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How Fast Does Benadryl Work? Onset Time and Duration
Benadryl starts working within 30 minutes after taking it orally, with peak effects reached in 1-2 hours. The antihistamine effects last 4-6 hours for most people. Injectable Benadryl works even faster than oral tablets, providing quicker relief for severe allergic reactions.
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Does Benadryl make you sleepy?
Benadryl (generic name: diphenhydramine) is an antihistamine that causes sleepiness in most people. Some people use Benadryl to help with sleep or insomnia, but this should only be for short-term use. Do not use Benadryl to make a child sleepy. Contact your doctor if you or your child are having trouble with sleep. Continue reading
See also:
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Drug information
- Benadryl Information for Consumers
- Benadryl prescribing info & package insert (for Health Professionals)
- Side Effects of Benadryl (detailed)
- Benadryl user reviews (80)
Related support groups
- Benadryl (114 questions, 167 members)