Thyroid Hormone (T3)Generally Approved

Liothyronine

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

FAA Pathway: Standard issuance by AME once thyroid levels stable

Liothyronine (T3) for hypothyroidism is generally compatible with FAA certification when thyroid levels are stable. Less commonly used than levothyroxine, but follows the same pathway. Stable TSH and free T3/T4 levels are required.

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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

Key Requirements
Stable thyroid function tests, no symptoms of hyper- or hypothyroidism
Certificate Classes
All classes eligible
Monitoring
Regular thyroid function labs
Notes
Report on Form 8500-8 Item 17a

Sources

  • FAA AME Guide, Endocrine

Last verified: 2026-03-01

Frequently Asked Questions

Is Liothyronine allowed for pilots?

The FAA considers Liothyronine (Cytomel) to be "Generally Approved" for medical certification purposes. Liothyronine (T3) for hypothyroidism is generally compatible with FAA certification when thyroid levels are stable. Less commonly used than levothyroxine, but follows the same pathway. Stable TSH and free T3/T4 levels are required.

What is the FAA status of Liothyronine?

Liothyronine has a status of "Generally Approved" under FAA medical certification policy. The certification pathway is: Standard issuance by AME once thyroid levels stable.

Can I fly while taking Liothyronine?

Liothyronine is generally compatible with flying. However, you must report it on your FAA medical application (Form 8500-8) and ensure you are not experiencing side effects that could impair flight safety. Always consult your Aviation Medical Examiner (AME).

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.