Standard Benadryl tablet strength

A standard over-the-counter Benadryl tablet contains 25 milligrams of diphenhydramine hydrochloride, the active ingredient that causes drowsiness and reduces allergy symptoms. This is the most common strength you will find on pharmacy shelves in the United States.

Benadryl also makes a 50-milligram tablet, sold as "Benadryl Extra Strength" or "Benadryl Maximum Strength". This version is less common in stores than the 25 mg tablet, but some pharmacies stock both. The difference between them matters because it changes how many tablets you take per dose.

The tablet itself is small and round, usually white or pale pink. The milligram amount is often printed on the tablet or clearly marked on the package. If you cannot read the tablet, the box will always state the strength on the front label in large text.

Key Takeaways

  • Standard Benadryl tablets contain 25 milligrams of diphenhydramine per tablet.
  • Extra Strength or Maximum Strength versions contain 50 milligrams per tablet.
  • The strength is printed on both the tablet and the package label, so you can verify what you have before taking a dose.
  • Liquid and gel formulations have different milligram amounts per dose, so do not assume tablet strength applies to other forms.
  • Dosage instructions on the package are based on tablet strength, so taking the wrong strength means taking the wrong dose.

Why tablet strength matters

Knowing the exact milligram amount is important because dosage instructions are based on it. If you take a 50 mg tablet when the instructions call for 25 mg, you are taking twice the intended dose. The package insert will tell you how many tablets to take and how often, based on the strength of the tablet you have.

Dosage also depends on your age and weight. Children's Benadryl tablets are typically lower strength than adult tablets. Always read the package instructions for your age group before taking any dose, and never assume that because one tablet worked before, the same number will work again if you have switched to a different strength.

Other Benadryl forms and their strengths

Benadryl comes in several forms beyond tablets, and each has its own milligram amounts. Benadryl liquid (the syrup you drink) usually contains 12.5 milligrams per 5 milliliters of liquid. Benadryl gel capsules typically contain 25 milligrams, the same as the standard tablet.

Benadryl also makes a dissolving tablet (sometimes called a melt or quick-dissolve tablet) that contains 25 milligrams. These dissolve on your tongue without water, but the dose is the same as a swallowed tablet. Do not mix forms or assume one form is stronger than another just because it feels different in your mouth or works faster.

Reading the label correctly

The front of a Benadryl box will say "25 mg" or "50 mg" in large text. The back of the box contains the "Drug Facts" label, which lists the active ingredient (diphenhydramine hydrochloride), the strength per dose, and the dosing instructions for different age groups.

If you are buying Benadryl for the first time or switching brands, spend 30 seconds reading the Drug Facts section. It will tell you exactly how many milligrams are in each dose and how many doses are safe in a 24-hour period. This information changes slightly between the 25 mg and 50 mg versions, so do not rely on memory from a previous purchase.

The Drug Facts label also lists any warnings or conditions that might make Benadryl unsafe for you. Reading it takes less time than taking the tablet, and it can prevent a mistake.

When to talk to a pharmacist

If you are taking other medications, have heart problems, high blood pressure, or glaucoma, ask a pharmacist before taking any Benadryl product. Diphenhydramine can interact with certain medications and may not be safe for people with certain health conditions, regardless of the milligram strength.

A pharmacist can also tell you whether the 25 mg or 50 mg tablet is right for your situation, and whether Benadryl is the best choice for your symptoms. Many people assume they need Benadryl for allergies, but other options may work better depending on what is causing the problem.

Frequently Asked Questions

Is a 50 mg Benadryl tablet twice as strong as a 25 mg tablet?

Yes. A 50 mg tablet contains exactly twice the amount of diphenhydramine as a 25 mg tablet. If you take one 50 mg tablet, you are receiving the same dose as taking two 25 mg tablets. Never take both a 25 mg and a 50 mg tablet at the same time unless the package instructions specifically tell you to do so.

Can I cut a Benadryl tablet in half to get a lower dose?

Some Benadryl tablets can be cut in half, but not all. Check the package to see if the tablet has a score line (a groove running down the middle). If it does, it is designed to be split. If there is no score line, do not cut it, because the dose may not divide evenly. When in doubt, ask a pharmacist.

What if I took the wrong strength by mistake?

If you took a 50 mg tablet when you meant to take 25 mg, you have received a higher dose than intended. Most people tolerate this without serious problems, but you may feel more drowsy than expected. Drink water and rest. If you feel unwell or have chest pain, call Poison Control at 1-800-222-1222 or seek emergency care.

Does the milligram amount change between generic and brand-name Benadryl?

No. Generic diphenhydramine tablets contain the same milligram amounts as brand-name Benadryl — 25 mg or 50 mg per tablet. The active ingredient is identical. The main difference is price and sometimes the inactive ingredients (fillers and binders), but the dose is the same.

Where can I find the milligram amount if the tablet is unmarked?

Check the package box first — the strength is always printed on the front label. If you have lost the box, the pharmacy that filled it can tell you the strength based on your prescription or purchase record. You can also call the pharmacy and describe the tablet, and they can identify it for you.