Diphenhydramine HCL Injectable

Rx approval required

We'll contact your veterinarian to review your medication request. If you aren't sure of the correct size and dose, please contact them directly or get in touch with our team.

Select Strength: 50mg/mL

Strength

Select size: (10mL)

Are you a prescriber?

Also available as a Oral Suspension (Anhydrous)Chew Treat Transdermal Pen (3mL)Transdermal Pen (6mL)Transdermal Pen (1.5mL)Transdermal Pen (9mL)Chew Treat (HYPO BASE for Protein Allergy)Oral Solution

Diphenhydramine HCl is an antihistamine commonly used in dogs and cats to alleviate allergy-related itching and mild allergic reactions. It is typically given orally and can also cause mild sedation, which is sometimes helpful for travel anxiety or motion sickness in pets, making it a versatile medication for allergy symptom relief in veterinary medicine.

Giving your pet an injection might feel intimidating at first, but with practice, it becomes routine. Follow these steps for safe and stress-free injections.

Get Your Supplies Ready

Medication vial or pre-filled syringe
Alcohol swabs
Sterile syringe & needle (if not pre-filled)
Sharps container for safe needle disposal

Drawing Up the Dose (if needed)

Clean the vial top with an alcohol swab
Attach needle to syringe
Pull in air equal to the dose
Insert needle into vial, push air in
Draw out the correct dose
Tap out air bubbles

Pick the Injection Site

Subcutaneous (under the skin): Loose skin between shoulder blades or side
Intramuscular (into muscle): As directed by your vet

Prep the Area

Pinch a fold of skin to form a “tent” (for subcutaneous). Wipe with alcohol if recommended.

Inject the Medication

Hold the syringe like a pencil
Insert the needle into the base of the skin tent at a 45° angle
Push the plunger slowly to inject

After the Injection

Remove the needle smoothly
Place it immediately in the sharps container (don’t recap)
Pat the area and give your pet praise or a treat

Safety Tips

Never reuse needles
Always dispose of used needles properly
Ask your vet for help if unsure

Mixlab is a licensed veterinary pharmacy dispensing both compounded and commercial medications, operating under the oversight of licensed pharmacists and in compliance with applicable state and federal pharmacy regulations. Compounded medications are prepared in compliance with USP standards and under PCAB-accredited practices. All medications dispensed by Mixlab require a valid prescription from a licensed veterinarian.