M-Dryl and Benadryl contain the same active ingredient, diphenhydramine hydrochloride, and work the same way in your body. M-Dryl is a store-brand (generic) version of Benadryl, made by a different company but held to the same FDA standards for safety and effectiveness.
Same Active Ingredient, Different Label
Both products rely on diphenhydramine hydrochloride as their only active ingredient. This is a first-generation antihistamine that blocks the chemical your body releases during an allergic reaction, reducing sneezing, runny nose, itchy or watery eyes, and throat irritation. The drug itself is identical regardless of which box it comes in.
The main difference is the company behind each label. Benadryl is manufactured by Johnson & Johnson (Kenvue), while M-Dryl is produced by VerityRx, LLC. Generic medications like M-Dryl must meet the same regulatory requirements as their name-brand counterparts, meaning the active ingredient is absorbed and used by your body in the same way.
Dosage Strength Differs by Form
M-Dryl is commonly sold as an oral liquid at 12.5 mg of diphenhydramine per 5 mL (one teaspoon). This liquid format is typical for children’s formulations and for adults who prefer not to swallow pills. Standard Benadryl Allergy tablets, by comparison, contain 25 mg per tablet. That’s not a sign that one product is stronger than the other. It simply reflects the different delivery formats. Two teaspoons of M-Dryl liquid delivers the same 25 mg dose as one Benadryl tablet.
If you’re switching between the two, pay attention to the per-dose strength listed on the label rather than assuming the amounts are interchangeable spoon-for-tablet. The maximum daily intake for diphenhydramine hydrochloride in adults and children 12 and older is 300 mg. For children ages 6 to 12, it’s 150 mg per day. Children under 6 should not exceed 37.5 mg daily.
What M-Dryl Is Labeled to Treat
M-Dryl is approved for the same set of allergy symptoms as Benadryl: sneezing, runny nose, itchy or watery eyes, and itching of the nose or throat caused by hay fever or other upper respiratory allergies. Diphenhydramine also causes drowsiness, which is why some people use it as a short-term sleep aid, though that use carries its own considerations, especially for older adults.
Where the Two Products Can Differ
The active ingredient is the same, but the inactive ingredients (fillers, flavorings, dyes, sweeteners) can vary between brands. These differences rarely matter for most people, but they can be relevant if you have a sensitivity or allergy to a specific dye or additive. If that applies to you, compare the full ingredient lists on both packages before choosing one.
Price is the other practical difference. Generic products like M-Dryl typically cost less than name-brand Benadryl because the manufacturer doesn’t carry the same branding and marketing expenses. The savings can be meaningful if you use the medication regularly, since the therapeutic effect is the same.
Choosing Between Them
For most people, M-Dryl and Benadryl are functionally interchangeable. You’re paying for the same drug at the same strength, just from a different manufacturer. Pick whichever is more affordable or available in the format you prefer. The one thing worth double-checking is the concentration per dose, especially when switching between a liquid and a tablet, so you don’t accidentally take more or less than intended.