FDA-filed SPL labeling · retrieved through openFDA

Diphenhydramine

Diphenhydramine is an antihistamine used to temporarily relieve allergy symptoms, cold symptoms, and — in one topical product — minor skin pain and itching.

Brand names UnisomSominexSilphenSiladrylBen Tann +11 more
Drug class ⓘ Histamine-1 Receptor Antagonist
Rx/OTC Forms 9 Routes Oral · Topical · Intramuscular; Intravenous · Intramuscular, Intravenous
Dr. Brian Staiger, PharmD, BCPS
Reviewed by Last reviewed Jul 10, 2026
🧬 Where this information comes from Click to expand

The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 739 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →

At a glance
Linked label effectiveJan 14, 2026
Clinical labels in scope ⓘ739
AvailabilityRx/OTC
Earliest approval/marketing year ⓘ1946
FDA-listed product records ⓘ2,096
Boxed warningNone found in compared labels
How we combine label and product data →
✓No current FDA shortage listed · checked Sep 22, 2026
Other forms & routes:
Injection Topical
⭐ Diphenhydramine at a glance The quick version — the full detail is in the Patient Information Guide below.
💊
HelloPharmacist Editorial Team Bottom Line
Diphenhydramine is a widely used antihistamine that effectively relieves allergy and cold symptoms like runny nose, sneezing, and itchy eyes. Its most important side effect is drowsiness — do not drive or drink alcohol while taking it. Children and older adults need extra caution, and you should always use the dosing device that comes with the product.
How we write & review this content — our editorial policy →

📖 Diphenhydramine: Patient Information Guide

A plain-language walkthrough of Diphenhydramine — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.

🎯What it's used for▾

Diphenhydramine is an antihistamine available in multiple products and forms, each approved for specific uses.

  • Temporarily relieves runny nose, sneezing, itchy/watery eyes, and itching of the nose or throat due to hay fever or other upper respiratory allergies — supported by capsule, tablet, chewable tablet, and oral solution products including Banophen, Benadryl, BENADRYL Allergy, AXIV Allergy Relief, Allergy Relief Caplet, Childrens Allergy Relief, Childrens Benadryl DYE-FREE ALLERGY, and others
  • Temporarily relieves runny nose and sneezing due to the common cold — supported by the same oral products listed above
  • After Bite Xtra gel (topical): temporarily relieves pain and itching from minor burns, minor cuts and scrapes, insect bites, minor skin irritations, and rashes from poison ivy, poison oak, and poison sumac
⚙️How it works▾

Diphenhydramine is an antihistamine — it competes with histamine for receptor sites on cells throughout the body. Histamine is the chemical responsible for allergy and cold symptoms like sneezing, itching, and runny nose; by blocking its receptors, diphenhydramine reduces those symptoms. It also has anticholinergic (drying) effects and a strong sedating effect because it crosses into the central nervous system (the brain and spinal cord).

💊How it's taken▾

Oral diphenhydramine products are generally taken every 4 to 6 hours, with no more than 6 doses in a 24-hour period. The right dose depends on your age and the specific product — always use the dosing chart on your product's label and the measuring device provided.

  • Chewable tablets must be fully chewed or crushed before swallowing — never swallowed whole
  • Liquid products must be measured with the enclosed dosing cup only — do not substitute another device
  • After Bite Xtra gel is applied to the skin up to 3 to 4 times daily — it is not taken by mouth
  • Do not exceed the recommended number of doses; if you miss a dose, simply take the next one when needed — do not double up
🤒Side effects — in detail▾

The most common side effects of diphenhydramine include:

  • Drowsiness and sleepiness
  • Dizziness and disturbed coordination
  • Dry mouth, nose, and throat
  • Thickening of mucus (bronchial secretions)
  • Upset stomach, nausea, or constipation
  • Blurred vision
  • Difficulty urinating or urinary retention
  • Excitability — especially in young children

More serious reactions to watch for include a rapid or irregular heartbeat (tachycardia or palpitations), a severe allergic reaction (anaphylaxis), significant changes in blood counts, and — particularly in overdose — convulsions (seizures). Seek medical help right away if any of these occur.

⚠️Warnings & precautions▾
  • Drowsiness and impaired alertness: Diphenhydramine causes significant drowsiness. Do not drive, operate heavy machinery, or drink alcohol while taking it.
  • Children and overdose risk: In children especially, overdose can cause hallucinations, convulsions, or death. Even at normal doses, young children may become excited rather than sedated. Keep out of reach of children.
  • Older adults (60+): More likely to experience dizziness, heavy sedation, and low blood pressure (hypotension) — use with caution.
  • Certain medical conditions: Use with great caution — and talk to your doctor first — if you have narrow-angle glaucoma, an enlarged prostate, bladder obstruction, a stomach ulcer, or any blockage in the digestive tract.
  • Injection route: Diphenhydramine injection must not be given under the skin or into the skin (subcutaneous or intradermal) — this can cause local tissue damage (necrosis).
🔀What it interacts with▾

Diphenhydramine interacts with several substances that can make its effects stronger or more dangerous:

  • Alcohol: Adds to the drowsiness effect — avoid while taking diphenhydramine
  • Sedatives, sleep aids, and tranquilizers: Increase central nervous system (CNS) depression when combined with diphenhydramine
  • MAO inhibitors (a class of antidepressants such as phenelzine or tranylcypromine): Prolong and intensify diphenhydramine's drying (anticholinergic) effects — do not use together

This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.

📋Before taking it▾
  • Do not use in newborns or premature infants
  • Do not use if you are breastfeeding — antihistamines are contraindicated in nursing mothers because of the high risk to infants
  • Do not use if you are allergic to diphenhydramine or other chemically similar antihistamines
  • Tell your doctor if you have narrow-angle glaucoma, an enlarged prostate, trouble urinating, a stomach ulcer, or a blockage in your stomach or intestines
  • Older adults (around age 60 and up) should use with caution due to higher risk of dizziness, sedation, and low blood pressure
  • Children are especially sensitive to overdose effects — use only as directed and keep out of reach of children
  • After Bite Xtra gel: do not use on children under 2 years without consulting a doctor
🚑If you take too much▾

Too much diphenhydramine can cause a range of reactions — from heavy sedation to overexcitation — along with dry mouth, fixed and dilated pupils, flushing, and gastrointestinal symptoms. In children, overstimulation and seizures are particularly likely. If you suspect an overdose, seek emergency medical help immediately.

📡Pharmacodynamics — effects in the body▾

Diphenhydramine blocks histamine receptors on cells, reducing the allergy and cold symptoms that histamine triggers — such as runny nose, sneezing, and itching. It also exerts drying (anticholinergic) effects and acts as a sedative because it penetrates the central nervous system. A single oral dose reaches peak activity in approximately one hour and the effects generally last four to six hours.

🔬Pharmacokinetics — how your body processes it▾

After an oral dose, diphenhydramine is absorbed quickly, with maximum activity reached in about one hour. It is widely distributed throughout the body, including into the brain. The drug is broken down (metabolized) in the liver, and its breakdown products are almost completely eliminated in the urine within 24 hours — very little of the original drug is excreted unchanged.

📦How to store it▾

store between 20-25°C (68-77°F). Protect from light.

📄 Written from Diphenhydramine’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →

147

Supplements & herbs that interact with Diphenhydramine

147 supplements and herbal products have documented interactions with Diphenhydramine in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.

Severity mix
  • Major · 9
  • Moderate · 119
  • Minor · 19
1,4-BUTANEDIOL Major ACTIVATED CHARCOAL Major BEER Major GAMMA-HYDROXYBUTYRATE (GHB) Major HENBANE Major KAVA Major L-TRYPTOPHAN Major SCOPOLIA Major +139 more
Every supplement checked against Diphenhydramine — ranked by severity The full interaction hub: 9 major · 119 moderate · 19 minor · every one linked to its full report. Check Diphenhydramine against your exact supplements

Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.

🩺 Pharmacist Counseling Corner

Quick, plain-English answers to the questions patients ask most about Diphenhydramine — the kind of thing our pharmacy team would talk through with you at the counter.

What exactly does diphenhydramine treat? ▾
Diphenhydramine is mainly used to temporarily ease the stuffy, sneezy, itchy symptoms of allergies — like hay fever — and the common cold. Think runny nose, sneezing, watery or itchy eyes, and an itchy throat or nose. One product, After Bite Xtra gel, is applied to the skin for relief from insect bites, minor burns, scrapes, and rashes from poison ivy or similar plants — that one is not taken by mouth.
Will this make me sleepy? ▾
Yes, and that's one of the most important things to know about this medicine. Drowsiness is one of its most common effects — it crosses into the brain and that's what causes the sedation. Please don't drive or operate heavy machinery after taking it, and avoid alcohol completely while you're using it, because alcohol will make the drowsiness much worse.
Is diphenhydramine safe for my child? ▾
It depends on your child's age and the product. Most oral diphenhydramine products are not recommended for children under 6, and liquid products labeled for children are generally for ages 6 to 11. Young children are also more sensitive — they can become excitable instead of sleepy, and an overdose can be very serious, including seizures. Always follow the dosing chart on the product label, never guess, and call your pediatrician if you're unsure.
How often can I take it, and is there a limit? ▾
Oral diphenhydramine is generally taken every 4 to 6 hours. The main rule to follow is no more than 6 doses in a 24-hour period. If liquid, always use the measuring cup that comes with the product — not a kitchen spoon, which is not accurate enough. After Bite Xtra gel is applied to skin no more than 3 to 4 times per day.
Are there medicines or health conditions I should mention to my doctor before taking this? ▾
Yes, a few important ones. Let your doctor know if you have narrow-angle glaucoma, an enlarged prostate, trouble urinating, a stomach ulcer, or any blockage in your stomach or intestines — diphenhydramine can make those conditions worse. Also tell them about every medicine you're on, especially sedatives, sleep aids, tranquilizers, or MAO inhibitors (a type of antidepressant), since combining these can amplify side effects. And if you're breastfeeding, this medicine should not be used.
I'm over 60 — is there anything extra I should watch out for? ▾
Absolutely worth knowing. Older adults are more sensitive to diphenhydramine's effects, and are more likely to experience significant dizziness, heavy sedation, and a drop in blood pressure. These can raise the risk of falls. If you feel very dizzy or lightheaded after taking it, sit or lie down and let someone know. It's always a good idea to check with your doctor or pharmacist before starting it regularly.
Is Diphenhydramine available over the counter? ▾
Both — Diphenhydramine is sold both over the counter and by prescription, according to its FDA labeling. Lower strengths or certain forms are often available without a prescription, while higher strengths or specialized forms still require one. Ask your pharmacist which version is right for you.
When was Diphenhydramine first available? ▾
Diphenhydramine has been available in the United States since at least 1946, based on FDA approval history (Drugs@FDA) and product marketing records.
Who makes Diphenhydramine? ▾
Diphenhydramine is supplied by 330 manufacturers listed in the FDA NDC Directory, including Walgreen Company, CVS Pharmacy, Rite Aid Corporation.

💬 Answers drafted from Diphenhydramine’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →

🧰 Keep exploring

📊Diphenhydramine supplement interactions147 checked — ranked by severity 🌿Drug & Supplement CheckerDiphenhydramine vs. vitamins & herbs 💬Ask a PharmacistFree answer, usually < 24h 🔎NDC & pricing lookupFind Diphenhydramine NDCs & costs 🅰️Browse Drugs A–ZLook up any medication

💊 How Diphenhydramine comes

Diphenhydramine is available in 9 forms. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.

Capsule

By mouth
Brands Diphenhist
How this form is used
What it may be used for
  • Temporarily relieves runny nose, sneezing, itchy/watery eyes, and itching of the nose or throat due to hay fever or other upper respiratory allergies
  • Temporarily relieves runny nose and sneezing due to the common cold
Important instructions
  • Diphenhydramine Hydrochloride capsules: take every 4 to 6 hours; do not take more than 6 doses in 24 hours
  • Diphenhydramine Hydrochloride 50 mg capsules: not appropriate for children under 12 — use the 25 mg package for children; do not attempt to break capsules
  • Children under 6 years of age: do not use capsule products
  • Follow the dosing chart on your specific product's label
Available strengths 4 strengths
25 mg 50 mg 50 mg/21 50 kg
700 FDA-listed product records ⓘ

Tablet

By mouth
Brands Benadryl
How this form is used
What it may be used for
  • Temporarily relieves runny nose, sneezing, itchy/watery eyes, and itching of the nose or throat due to hay fever or other upper respiratory allergies
  • Temporarily relieves runny nose and sneezing due to the common cold
Important instructions
  • Take every 4 to 6 hours; do not take more than 6 doses in 24 hours
  • Follow your specific product's dosing chart for the correct dose by age
  • Children under 6 years: do not use tablet products unless directed by a doctor
Available strengths 3 strengths
25 mg 25 mg/25 mg 50 mg
638 FDA-listed product records ⓘ

Oral solution

By mouth
Brands Allergy Allergy Relief BENADRYL Allergy childrens allergy Childrens Allergy Relief Childrens Benadryl DYE-FREE ALLERGY
How this form is used
What it may be used for
  • Temporarily relieves runny nose, sneezing, itchy/watery eyes, and itching of the nose or throat due to hay fever or other upper respiratory allergies
  • Temporarily relieves runny nose and sneezing due to the common cold
Important instructions
  • BENADRYL Allergy solution and Childrens Benadryl DYE-FREE ALLERGY solution: take every 4 to 6 hours; do not take more than 6 doses in 24 hours
  • Always measure with the enclosed dosing cup — do not use any other dosing device
  • Children under 2 years: do not use; children 2 to 5 years: do not use unless directed by a doctor
  • Childrens Allergy Relief, childrens allergy, and similar children's solutions: intended for children 6 to 11 years; follow the dosing chart on your specific product
Available strengths 10 strengths
2.5 mg/mL 6.25 mg/mL 12.5 mg/5 mL 12.5 mg/10 mL 12.5 mg/15 mL 25 mg/5 mL
Show 4 more strengths Show fewer strengths
25 mg/10 mL 50 mg/3 mL 50 mg/20 mL 50 mg/30 mL
515 FDA-listed product records ⓘ

Chewable tablet

By mouth
Brands Allergy Relief Childrens Allergy Relief Walmart
How this form is used
What it may be used for
  • Temporarily relieves runny nose, sneezing, itchy/watery eyes, and itching of the nose or throat due to hay fever or other upper respiratory allergies
  • Temporarily relieves runny nose and sneezing due to the common cold
Important instructions
  • Walmart chewable tablets: chew one tablet completely at onset of symptoms — do not swallow whole
  • Childrens Allergy Relief and Allergy Relief chewable tablets: chew or crush tablets completely before swallowing — do not swallow whole
  • Take every 4 to 6 hours; do not take more than 6 doses in 24 hours
  • Children under 2 years: do not use; children 2 to 5 years: do not use unless directed by a doctor
Available strengths 2 strengths
12.5 mg 25 mg
93 FDA-listed product records ⓘ

Injection

Into a muscle · Into a vein
How this form is used
What it may be used for
  • Temporarily relieves allergy and cold symptoms including runny nose, sneezing, itchy/watery eyes, and itching of the nose or throat
Important instructions
  • Given by intramuscular or intravenous route — administered by a healthcare professional in a clinical setting
  • Do not inject subcutaneously or intradermally — local tissue damage (necrosis) can occur
Available strengths 1 strength
50 mg/mL
69 FDA-listed product records ⓘ

Topical cream, ointment or gel

By mouth · On the skin
Brands After Bite Xtra
How this form is used
What it may be used for
  • After Bite Xtra gel: temporarily relieves pain and itching from minor burns, minor cuts and scrapes, insect bites, and minor skin irritations
  • After Bite Xtra gel: temporarily relieves rashes from poison ivy, poison oak, and poison sumac
Important instructions
  • After Bite Xtra gel: apply to the affected area no more than 3 to 4 times daily
  • After Bite Xtra gel: for adults and children 2 years and older only — children under 2 years: consult a doctor
Available strengths 10 strengths
2 mg/100 mL 12.5 mg 20 mg/g 20 mg/mL 25 mg 0.4 g/20 g
Show 4 more strengths Show fewer strengths
1.14 g/57 g 2 g/100 g 2 g/100 mL 2.03 g/100 g
33 FDA-listed product records ⓘ

Other oral form

By mouth
Available strengths 2 strengths
12.5 mg 25 mg
13 FDA-listed product records ⓘ

Topical solution

On the skin
Available strengths 1 strength
20.3 g/L
2 FDA-listed product records ⓘ

📊 Diphenhydramine across the U.S. market

How Diphenhydramine appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.

9
Dose forms ⓘ
330
Manufacturers
40
Brand names
2,096
FDA-listed product records ⓘ
1946
First marketed ⓘ

FDA-listed product records by dose form (tablet variants merged) — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

Also listed with the FDA, not a patient dose form: Powder (20) · Kit (4) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.

Walgreen Company7%
CVS Pharmacy6%
Rite Aid Corporation4%
Wal-Mart Stores Inc4%
Lil' Drug Store Products, Inc.4%
Target Corporation4%
Other makers71%

Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

📈 How widely Diphenhydramine is used

A general measure of how commonly Diphenhydramine is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.

Think of this as a proxy for how widely Diphenhydramine is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.

1,303,409
Medicaid prescriptions filled (Q1–Q4 2025)
$34.8M gross Medicaid reimbursement (before mandatory rebates — net cost is lower)

How commonly is Diphenhydramine prescribed? Of the 1,596 medications we measure, Diphenhydramine ranks #142 by Medicaid prescriptions — more than 91% of them.

Where Diphenhydramine ranks among the drugs we measure · Q1–Q4 2025 · neighbors ±5
Total prescriptions — #142 of 1,596
#137 Simvastatin 1,357,663 Rx #138 Tretinoin 1,345,058 Rx #139 Tretinoin Topical 1,344,781 Rx #140 Dapagliflozin 1,339,664 Rx #141 Benztropine 1,314,428 Rx #142 Diphenhydramine 1,303,409 Rx #143 Dexamethasone Injectio... 1,290,031 Rx #144 Ketorolac Injection 1,259,288 Rx #145 Dicyclomine 1,233,412 Rx #146 Albuterol and Ipratrop... 1,217,671 Rx #147 Diazepam 1,216,820 Rx

Utilization by Diphenhydramine product

Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.

The 2.5 mg/mL oral solution is the most-dispensed Diphenhydramine product — about 29% of these Medicaid prescriptions.

diphenhydramine hydrochloride 2.5 MG/ML Oral Solution Most dispensed

383,271 Medicaid prescriptions (Q1–Q4 2025) 29% of Diphenhydramine prescriptions shown $3.1M gross reimbursement (before rebates) ≈ $8.21 per prescription (gross)

Summed across the 37 of 269 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1049906

diphenhydramine hydrochloride 25 MG Oral Capsule

259,953 Medicaid prescriptions (Q1–Q4 2025) 20% of Diphenhydramine prescriptions shown $3M gross reimbursement (before rebates) ≈ $12 per prescription (gross)

Summed across the 14 of 356 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1049909

diphenhydramine hydrochloride 50 MG/ML Injectable Solution

172,217 Medicaid prescriptions (Q1–Q4 2025) 13% of Diphenhydramine prescriptions shown $13.3M gross reimbursement (before rebates) ≈ $77 per prescription (gross)

Summed across the 2 of 13 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1049633

1 ML diphenhydramine hydrochloride 50 MG/ML Injection

166,857 Medicaid prescriptions (Q1–Q4 2025) 13% of Diphenhydramine prescriptions shown $11.9M gross reimbursement (before rebates) ≈ $71 per prescription (gross)

Summed across the 7 of 42 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1723740

diphenhydramine hydrochloride 50 MG Oral Capsule

164,709 Medicaid prescriptions (Q1–Q4 2025) 13% of Diphenhydramine prescriptions shown $1.8M gross reimbursement (before rebates) ≈ $11 per prescription (gross)

Summed across the 7 of 246 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1020477

diphenhydramine hydrochloride 25 MG Oral Tablet

150,359 Medicaid prescriptions (Q1–Q4 2025) 12% of Diphenhydramine prescriptions shown $1.3M gross reimbursement (before rebates) ≈ $8.64 per prescription (gross)

Summed across the 19 of 480 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1049630

1 ML diphenhydramine hydrochloride 50 MG/ML Prefilled Syringe

3,479 Medicaid prescriptions (Q1–Q4 2025) <1% of Diphenhydramine prescriptions shown $322,679 gross reimbursement (before rebates) ≈ $93 per prescription (gross)

Summed across the 1 of 4 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1049289

diphenhydramine hydrochloride 12.5 MG Chewable Tablet

24 Medicaid prescriptions (Q1–Q4 2025) <1% of Diphenhydramine prescriptions shown $241 gross reimbursement (before rebates) ≈ $10 per prescription (gross)

Summed across the 1 of 44 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1049900

diphenhydramine hydrochloride 1.67 MG/ML Oral Solution

23 Medicaid prescriptions (Q1–Q4 2025) <1% of Diphenhydramine prescriptions shown $263 gross reimbursement (before rebates) ≈ $11 per prescription (gross)

Summed across the 1 of 127 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1248354

Other Diphenhydramine products — combination packs and listings not yet matched to a specific clinical product (kept visible so every prescription is accounted for)

2,517 Medicaid prescriptions (Q1–Q4 2025) <1% of Diphenhydramine prescriptions shown $19,037 gross reimbursement (before rebates) ≈ $7.56 per prescription (gross)

Summed across the 2 of 587 listed NDC products with Medicaid activity.

Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.

Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Diphenhydramine, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 91 of 2,168 listed Diphenhydramine NDCs with Medicaid activity.

🔍 Compare Diphenhydramine products

A representative set of FDA-listed product records for Diphenhydramine — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)

Showing 200 of 2,096 products — FDA National Drug Code Directory. See every product, package size and price: browse all 2,096 Diphenhydramine NDCs →

RxNorm Concept Web — From Ingredient to Every Form and Strength

This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.

Ingredient (IN) Diphenhydramine RxCUI 3498 11 dose forms · 28 strengths
  1. Dose form (SCDF) Chewable Tablet RxCUI 371893 In current FDA listings
    Clinical drug / strength (SCD) hydrochloride 12.5 MG RxCUI 1049900 hydrochloride 25 MG RxCUI 2046528 tannate 25 MG RxCUI 1251787
  2. Dose form (SCDF) Disintegrating Oral Tablet RxCUI 477246 In current FDA listings
    Clinical drug / strength (SCD) hydrochloride 12.5 MG RxCUI 882504 hydrochloride 25 MG RxCUI 1093098
  3. Dose form (SCDF) Injectable Solution RxCUI 371895 In current FDA listings
    Clinical drug / strength (SCD) hydrochloride 0.5 MG/ML RxCUI 1249715 hydrochloride 1 MG/ML RxCUI 1249717 hydrochloride 50 MG/ML RxCUI 1049633
  7. Dose form (SCDF) Oral Tablet RxCUI 371892 In current FDA listings
    Clinical drug / strength (SCD) hydrochloride 10 MG RxCUI 1310475 hydrochloride 25 MG RxCUI 1049630 hydrochloride 30 MG RxCUI 1310483 hydrochloride 50 MG RxCUI 1085945
  9. Dose form (SCDF) Topical Cream RxCUI 377689 In current FDA listings
    Clinical drug / strength (SCD) hydrochloride 10 MG/ML RxCUI 1049888 hydrochloride 20 MG/ML RxCUI 1050077
  10. Dose form (SCDF) Topical Gel RxCUI 377976 In current FDA listings
    Clinical drug / strength (SCD) hydrochloride 0.02 MG/MG RxCUI 1049880
  11. Dose form (SCDF) Topical Spray RxCUI 377318 In current FDA listings
    Clinical drug / strength (SCD) hydrochloride 10 MG/ML RxCUI 1049898 hydrochloride 20 MG/ML RxCUI 1050080

Look up RxCUI 3498 in the RxCUI Atlas →

RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.

🏷️ Sold under these brand names

Unisom Sominex Silphen Siladryl Ben Tann Benadryl PediaCare Children's Allergy Dicopanol Nytol Aler-Dryl Diphenhist Diphenadryl Pardryl Hydramine Dytan Diphenylin

🏭 Manufacturers & labelers

Walgreen Company 71 CVS Pharmacy 62 Rite Aid Corporation 46 Wal-Mart Stores Inc 44 Lil' Drug Store Products, Inc. 38 Target Corporation 37 Amerisource Bergen 37 Topco Associates LLC 35 Meijer Distribution Inc 33 Walgreens 33 Spirit Pharmaceuticals Llc 32 A-S Medication Solutions 30 Dolgencorp, Inc. (DOLLAR GENERAL & REXALL) 28 Dolgencorp, LLC 27 L.N.K. International, Inc. 27 Strategic Sourcing Services LLC 26 P & L Development, LLC 26 WinCo Foods, LLC 25 Major Pharmaceuticals 24 QUALITY CHOICE (Chain Drug Marketing Association) 24 Kroger Company 23 H E B 23 The Procter & Gamble Manufacturing Company 22 Cardinal Health 110, LLC. DBA Leader 19

…and 16 more on the FDA NDC directory.

RxNorm drug class

Diphenhydramine belongs to the Histamine-1 Receptor Antagonist class.

Pharmacologic class Histamine-1 Receptor Antagonist
Drug family (ATC) Propionic acid derivatives, Antihistamines for topical use, Aminoalkyl ethers
How it works Histamine H1 Receptor Antagonists

Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.

🔬 Where this comes from

Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.

📄
FDA-filed drug labels (SPL) Uses, dosing, warnings & side effects from SPL records retrieved through openFDA; the linked representative set can be verified on DailyMed. ✓ Linked label effective Jan 14, 2026
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Forms, brands & labelersAggregated from ingredient-matched FDA National Drug Code Directory product records for Diphenhydramine.
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Real-world reportsThe FDA Adverse Event Reporting System (FAERS), served through openFDA.
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Recalls & shortagesopenFDA drug-enforcement reports and the FDA drug-shortage database.
🧾 Clinical label set — FDA-filed SPL labels retained for Diphenhydramine after exact ingredient or ingredient-combination matching and applicable route/form matching
Clinical labels in scope
739
NDC products indexed
2,096
Distinct labelers/manufacturers represented
330
Linked representative label ⓘ
NorMed
Linked label effective
Jan 14, 2026
Composite sections available
18
Linked SPL Set ID
38786a65-a12b-4479-b63c-b7c15410da04
Linked SPL Document ID
675ce74c-0894-4272-85ba-086f33459a9a
Open the linked representative label on DailyMed ↗
NDC package records associated with this linked SPL 1

How we combine label and product data

HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 739 FDA-filed SPL label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.

For canonical ingredient pages, bounded product-attributed indication and administration excerpts may be added to the AI evidence, and the generator is instructed to preserve available product, brand, route, and form qualifiers instead of treating one label as universal. Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. NorMed is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.

This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.