Medically Necessary Liquids on a Plane: TSA Exemption Rules
Volume & Exemption Status
Medically Exempt — Permitted in Reasonable Quantities
Governed by international 100 ml (3.4 fl oz) LAGs regulations
💧 3-1-1 liquids rule checker
One quart-size (≈1 L) bag per passenger; every container must be 3.4 oz (100 ml) or less.
Fit is approximate — container shape decides real-world packing. Medically necessary liquids and infant food are exempt: declare them. Packing a whole bag? Plan it container by container →
TSA & Aviation Security Rule Summary
Medically necessary liquids, gels, and aerosols (including insulin, liquid prescriptions, eye drops, saline, and enteral nutrition) are explicitly exempt from the 3-1-1 100 ml container limit in reasonable quantities for your itinerary. Declare them to the screener before X-ray.
Related Verified Products
Deep dive: Flying with medication & medical equipment
Read what counts as a liquid, gel, aerosol, or paste at airport security.
Frequently Asked Questions
Do I need a doctor letter to bring liquid medication over 100 ml?
A doctor letter is not strictly required by TSA for domestic US flights, but prescription pharmacy labels are strongly recommended to expedite screening.