How to Take Benadryl: Side Effects, Dosage
How to take Benadryl as directed: dosage guidelines, common side effects, precautions and when to seek medical help.
Not medical advice. Speak with a healthcare professional before using any medication.
Reviewed by:
Updated Feb, 15
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Information sourced from FDA-approved prescribing information and peer-reviewed medical references.
How to Take Benadryl
How to Take Benadryl (Diphenhydramine)
The following steps reflect standard OTC label instructions for Benadryl (diphenhydramine):
- Per OTC labeling, adults and teens 12+ years: 25–50 mg by mouth every 4–6 hours as needed. Do not exceed 300 mg in 24 hours.
- Per OTC labeling, children 6–11 years: 12.5–25 mg by mouth every 4–6 hours as needed. Maximum 150 mg in 24 hours.
- Per OTC labeling, children 2–5 years: Use only the liquid form. A typical dose is approximately 1 mg per kg per dose, given every 6 hours. Avoid exceeding four doses in 24 hours.
- Per OTC labeling, under 2 years: Do not use unless specifically guided by a clinician.
- How to measure liquid: Use the provided oral syringe or dosing cup for an accurate amount.
- Per OTC labeling, with or without food: You may take it either way.
- Per OTC labeling, if using at bedtime: Many people take the dose about 30 minutes before they plan to sleep.
- Per OTC labeling, if you miss a dose: Take it when needed next.
- Per OTC labeling, driving and focus: This medicine can cause drowsiness. Until you know how you respond, use it at a time when you can rest afterward.
Warnings Before Taking Benadryl
- Per OTC labeling, avoid if you've had an allergic reaction to diphenhydramine or similar antihistamines.
- Per OTC labeling, use caution with glaucoma, prostate enlargement, or urinary retention, as symptoms may worsen.
- Per OTC labeling, avoid combining with alcohol or sedatives due to increased drowsiness.
- Per OTC labeling, check with your clinician if you have heart disease, high blood pressure, or thyroid issues.
Benadryl Side Effects
Common
Moderate
Drowsiness
Per OTC labeling, Benadryl commonly causes sleepiness because diphenhydramine crosses into the brain and affects certain chemical signals. Per OTC labeling, do not drive or operate machinery after taking this product until you know how it affects you.
Per OTC Drug Facts labeling. If symptoms persist or worsen, stop use and consult a healthcare provider.
Normally lasts for:
4–8 hours
Common
Mild
Dry Mouth
Per OTC labeling, this antihistamine decreases saliva production, leaving the mouth feeling dry or sticky.
Per OTC Drug Facts labeling. If symptoms persist or worsen, stop use and consult a healthcare provider.
Normally lasts for:
4–6 hours
Common
Mild
Dizziness
Per OTC labeling, some people feel lightheaded or unsteady, especially when standing up quickly.
Per OTC Drug Facts labeling. If symptoms persist or worsen, stop use and consult a healthcare provider.
Normally lasts for:
2–6 hours
Uncommon
Mild
Blurred Vision
Per OTC labeling, Benadryl can temporarily affect the eyes' ability to focus, causing fuzzy or unclear vision.
Per OTC Drug Facts labeling. If symptoms persist or worsen, stop use and consult a healthcare provider.
Normally lasts for:
4–8 hours
Uncommon
Mild
Constipation
Per OTC labeling, the anticholinergic effect of diphenhydramine can slow the digestive tract, leading to harder or less frequent stools.
Per OTC Drug Facts labeling. If symptoms persist or worsen, stop use and consult a healthcare provider.
Normally lasts for:
1–2 days
Uncommon
Moderate
Difficulty Urinating
Per OTC labeling, Benadryl may make it harder to start or fully empty the bladder, especially in people with prostate issues. Consult a healthcare provider if urinary retention occurs.
Per OTC Drug Facts labeling. If symptoms persist or worsen, stop use and consult a healthcare provider.
Normally lasts for:
4–8 hours
Contact Us for a Personalized Care Plan
Have questions about compounding? Contact Voshell's Pharmacy — we prepare patient-specific medications pursuant to valid prescriptions from your licensed prescriber.
What If You Forgot to Take Benadryl
What If You Forgot to Take Benadryl?
If you miss a dose of Benadryl, take it as soon as you remember unless it's almost time for your next planned dose. In that case, skip the missed dose and simply return to your usual schedule.
Do not double up to make up for a missed dose — that can cause excessive drowsiness.
Per OTC labeling, if you only use Benadryl as needed, you can take it when symptoms arise.
Per OTC labeling, doses should be spaced at least 4–6 hours apart. If you're ever unsure, wait until your next regular dose or consult a healthcare provider.
What If You Took Too Much Benadryl
What If You Took Too Much Benadryl?
If more than the labeled amount was used, contact Poison Control at 1-800-222-1222 right away. For children or if the product was swallowed, seek urgent medical care immediately.
- Do not use additional doses until you have spoken with Poison Control or a clinician.
- If symptoms such as rapid heartbeat, extreme confusion, or difficulty staying awake occur, seek emergency medical care.
- Keep this and all medications out of reach of children.
How Much Does Benadryl Cost
How Much Does Benadryl Cost With Insurance?
With many U.S. insurance plans, Benadryl (diphenhydramine) coverage varies. Many plans offer OTC coverage only in specific circumstances.
Store-brand diphenhydramine may be available at a lower cost than name-brand Benadryl products
If your insurance doesn't cover OTC items, a store-brand version is typically available at a lower price.
Prices vary by pharmacy, dose, location, and insurance plan and may have changed since this page was written. Contact your pharmacy or insurance provider for current pricing.
How Much Does Benadryl Cost without Insurance
Cost of Benadryl Without Insurance
Without insurance, Benadryl and diphenhydramine are generally available at modest prices. Prices vary by store and whether you choose brand-name or generic.
Brand-name Benadryl: available in small boxes of tablets or capsules.
Diphenhydramine (store-brand): a more budget-friendly option with the same active ingredient.
Costs can differ between pharmacies, big-box stores, and online retailers.
Prices vary by pharmacy, dose, location, and insurance plan and may have changed since this page was written. Contact your pharmacy or insurance provider for current pricing.
Resources:
https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/diphenhydramine-benadryl
https://medlineplus.gov/druginfo/meds/a682539.html
https://www.mayoclinic.org/drugs-supplements/diphenhydramine-oral-route/description/drg-20070581
https://www.nhs.uk/medicines/diphenhydramine/
https://www.ncbi.nlm.nih.gov/books/NBK482457/
