rxstat › Shortages › Diphenhydramine

Diphenhydramine shortage status

Partial shortage

Source: Health Canada shortage reports · Updated Jul 9, 2026

Some Diphenhydramine products are in shortage in Canada (2 of 9 reported products), while others remain available. Your pharmacy may be able to substitute an unaffected manufacturer.
Products affected
2 / 9
In shortage since
Apr 11, 2014
Reports on file
18
Talk to your pharmacist. Pharmacists can often substitute another manufacturer's version, a different strength, or (in most provinces) adapt or renew a prescription on the spot. Your free provincial health line is 811.

Reports by product

Active shortage
UNISOM SLEEPGELS EXTRA STRENGTH
50MG · CAPSULE · PALADIN LABS INC.
DIN 02061597 · since Oct 25, 2023, no end estimate · Delay in shipping of the drug.
Active shortage
NADRYL 50MG
50MG · TABLET · LABORATOIRE RIVA INC
DIN 02239030 · since Apr 11, 2014, no end estimate · Disruption of the manufacture of the drug.
Resolved
DIPHENHYDRAMINE HYDROCHLORIDE INJECTION USP
50MG · LIQUID · SANDOZ CANADA INCORPORATED
DIN 00596612 · ended Dec 19, 2025 · Requirements related to complying with good manufacturing practices.
Avoided
DIPHENIST
50MG · LIQUID · OMEGA LABORATORIES LIMITED
DIN 02219336 · ended Jul 9, 2025 · Disruption of the manufacture of the drug.
Discontinued
ALLERNIX
25MG · TABLET · TEVA CANADA LIMITED
DIN 02097583
Discontinued
ALLERNIX EXTRA STRENGTH
50MG · TABLET · TEVA CANADA LIMITED
DIN 02097575
Resolved
DIPHENHYDRAMINE HYDROCHLORIDE INJECTION USP
50MG · LIQUID · SANDOZ CANADA INCORPORATED
DIN 00596612 · ended Sep 19, 2023 · Disruption of the manufacture of the drug.
Resolved
DIPHENIST 50MG/ML
50MG · LIQUID · OMEGA LABORATORIES LIMITED
DIN 02219336 · ended Aug 31, 2023 · Demand increase for the drug.
Resolved
DIPHENIST 50MG/ML
50MG · LIQUID · OMEGA LABORATORIES LIMITED
DIN 02219336 · ended Mar 17, 2023 · Demand increase for the drug.
Resolved
DIPHENHYDRAMINE HYDROCHLORIDE INJECTION
50MG · SOLUTION · FRESENIUS KABI CANADA LTD
DIN 02369567 · ended Feb 28, 2023 · Other (Please describe in comments)
Resolved
DIPHENHYDRAMINE HYDROCHLORIDE INJECTION USP
50MG · LIQUID · SANDOZ CANADA INCORPORATED
DIN 00596612 · ended Feb 8, 2023 · Disruption of the manufacture of the drug.
Resolved
DIPHENIST 50MG/ML
50MG · LIQUID · OMEGA LABORATORIES LIMITED
DIN 02219336 · ended Oct 21, 2022 · Demand increase for the drug.

Showing 12 of 18 reports. All reports are on file with Health Canada.

What's happening

Diphenhydramine is currently affected by 2 active shortage reports filed with Health Canada by PALADIN LABS INC., LABORATOIRE RIVA INC.

The reported causes are: delay in shipping of the drug; disruption of the manufacture of the drug. Manufacturers must report shortages, but end-date estimates are their own projections and often move.

If your usual product is affected, a pharmacist is the fastest route to a solution: they can dispense an unaffected manufacturer's equivalent when one exists, and in most provinces can adapt doses or substitute a therapeutic alternative without a new appointment.

Diphenhydramine is classified under “ANTIHISTAMINES FOR SYSTEMIC USE” (ATC R06AA).

Recent changes

Common questions

When will Diphenhydramine be back in stock in Canada?

Manufacturers have not provided a reliable end date. This page updates automatically as soon as an estimate is filed.

Why is Diphenhydramine in shortage?

See the reports above; manufacturers must state a reason (most commonly manufacturing disruption or a surge in demand) when filing with Health Canada.

What can my pharmacist do about it?

Often quite a lot: substitute an equivalent product from an unaffected manufacturer, adjust quantities, or in most provinces adapt or renew prescriptions on the spot. Call your pharmacy before visiting, and call 811 for free health advice.

Related drugs (antihistamines for systemic use)

Partial shortageBilastine1 of 2 reported products affectedPartial shortageCetirizine1 of 15 reported products affected · est. return Dec 31, 2023Partial shortageDoxylamine Pyridoxine1 of 2 reported products affected · est. return Jul 3, 2026Partial shortageKetotifen1 of 1 reported products affectedNo current shortageDimenhydrinateNo current shortageKetotifen

Guides: what to do when your medication is in shortage · how to read shortage reports

Data reflects reports manufacturers are legally required to file with Health Canada, republished with per-drug aggregation by rxstat. Estimated end dates are supplied by manufacturers and frequently change. This page describes drug supply only and is not medical advice; never stop or switch a medication without speaking to your pharmacist or prescriber.