First-Generation Antihistamine (Allergy / Sleep)Disqualifying60h wait period

Diphenhydramine

Brand names: Benadryl|Last verified: 2026-03-01

FAA Pathway: Do Not Fly — sedating antihistamine

Diphenhydramine is a first-generation antihistamine that is NOT acceptable for flying. Its significant sedating effects make it incompatible with aviation. Pilots must wait at least 60 hours after the last dose before flying.

Check your medications

Look up any medication in our FAA compatibility database.

Medication Checker

Related Resources

Pilot Tip

Always report all medications on your FAA medical application (Form 8500-8, Item 17a), even OTC medications. Failure to disclose is a far bigger issue than the medication itself.

Certification Details

FAA Status

Do Not Fly — first-generation antihistamines prohibited

Wait Period

Minimum 60 hours after last dose

Certificate Classes

All classes affected during use

Alternative

Use loratadine (Claritin) or fexofenadine (Allegra) instead

Sources

FAA OTC Medication Guide

Last verified: 2026-03-01

Frequently Asked Questions

Is Diphenhydramine allowed for pilots?

The FAA considers Diphenhydramine (Benadryl) to be "Disqualifying" for medical certification purposes. Diphenhydramine is a first-generation antihistamine that is NOT acceptable for flying. Its significant sedating effects make it incompatible with aviation. Pilots must wait at least 60 hours after the last dose before flying.

What is the FAA status of Diphenhydramine?

Diphenhydramine has a status of "Disqualifying" under FAA medical certification policy. The certification pathway is: Do Not Fly — sedating antihistamine.

Can I fly while taking Diphenhydramine?

Diphenhydramine is currently disqualifying for FAA medical certification. You cannot fly while taking this medication. A washout period and evaluation are typically required after discontinuation. Consult an AME or aviation attorney before making any medication changes.

Important Notice

The FAA does not publish a comprehensive list of “approved” medications. The information on this page represents our interpretation of publicly available FAA guidance and is provided for informational and educational purposes only. It does not constitute medical advice, legal advice, or a guarantee of certification outcome.

The primary issue with the FAA is always whether the underlying medical condition — not just the medication — is compatible with safe flight. You should only start, stop, or change medications after consulting your treating physician. Always consult with a qualified Aviation Medical Examiner (AME) for guidance specific to your situation. FAA policies are subject to change. ClearedMed is not affiliated with or endorsed by the FAA.