You can bring codeine into Mexico for personal medical use, but only with a prescription or doctor’s letter translated into Spanish, only in the quantity you need for your trip, and only in the original labeled packaging.1U.S. Embassy & Consulates in Mexico. Bringing Items into Mexico / U.S. Mexico officially lists codeine as a prohibited import, and the personal-use exception is narrow. Miss a piece of the paperwork and you can lose the medication at the border. In more serious cases, you can face criminal charges.
What Your Prescription or Doctor’s Letter Must Say
A prescription or a letter from your prescribing physician is the document that turns a prohibited substance into an allowed personal import. It has to spell out three quantities: the total amount of codeine you need during your stay, the amount you are physically carrying, and your daily dose.1U.S. Embassy & Consulates in Mexico. Bringing Items into Mexico / U.S. “Take as needed” will not hold up when a customs agent is counting pills.
The document also has to identify your doctor concretely:
- Full name and handwritten signature
- Phone number and office address
- Professional registration or license number
And the whole thing must be translated into Spanish.1U.S. Embassy & Consulates in Mexico. Bringing Items into Mexico / U.S. Some officers accept English documents; the written rule does not require them to. Paying for a professional translation before you travel is far cheaper than replacing a seized prescription abroad.
How Much You Can Carry
The quantity is tied to the length of your stay. You may not bring more codeine than you need for the days you will be in Mexico.1U.S. Embassy & Consulates in Mexico. Bringing Items into Mexico / U.S. There is no flat 30-day allowance. Ten days in country at two doses a day means twenty doses, not a full bottle. A 90-day supply for a one-week trip is the kind of gap that invites a closer look at secondary inspection.
How to Pack It
Keep codeine in its original pharmacy packaging with the label intact, in your carry-on, inside a transparent bag.1U.S. Embassy & Consulates in Mexico. Bringing Items into Mexico / U.S. The label is what an inspector uses to match the medication against your prescription. Loose pills in an unmarked bottle will not clear inspection even with perfect paperwork.
Combination Products That Are Banned Outright
Some codeine products are illegal to bring into Mexico no matter what documentation you carry. Any medication containing pseudoephedrine or ephedrine is prohibited.2Government of Mexico. Acuerdo por el que se Establecen Medidas de Proteccion en Materia de Salud Humana para Prevenir el Uso y Consumo de Pseudoefedrina y Efedrina That covers the U.S. cold-and-cough combinations that pair codeine with a decongestant. Sudafed and certain Actifed formulations are named specifically as prohibited.1U.S. Embassy & Consulates in Mexico. Bringing Items into Mexico / U.S. Read the active and inactive ingredient panels on every product you plan to pack. If a stimulant appears anywhere, leave it home.
Declaring Codeine at the Border
Arriving by air or sea, you fill out the customs declaration form (“Declaración de aduanas para pasajeros procedentes del extranjero”) and hand it to a customs officer.3Agencia Nacional de Aduanas de México. Declaración de Mercancía Arriving by bus at a land crossing, you exit at the checkpoint and complete the same form. Declare the controlled medication on the form.
After you submit it, you press the “semáforo fiscal,” a random traffic light. Green passes you through. Red sends you to secondary inspection, where agents open your bags and count against your prescription.3Agencia Nacional de Aduanas de México. Declaración de Mercancía The light is random, so a clean declaration does not exempt you. Keep the prescription, the translated version, the doctor’s letter, and the medication itself in a single accessible place in your carry-on.
Penalties for Getting It Wrong
Article 194 of Mexico’s Federal Penal Code sets the punishment for importing a narcotic without authorization at 10 to 25 years in prison plus a fine of 100 to 500 days of the UMA, the national economic reference unit.4Justia Mexico. Código Penal Federal – Artículos 193 al 199 An attempted import can draw up to two-thirds of that range when intent is clear. The 2026 daily UMA is $117.31 MXN, so a 500-day fine reaches roughly $58,655 MXN, about $3,300 USD at recent exchange rates.5National Institute of Statistics and Geography (INEGI). Measure Unit and Upgrade (UMA)
For a traveler who simply forgot the translation or brought too many pills, seizure at the border is the more common outcome. Officers have discretion to escalate, and the statutory ceiling is what it is.
Getting Codeine From a Mexican Doctor Instead
If the paperwork at the border is more trouble than it is worth, a licensed physician in Mexico can write you a local prescription. Mexican controlled-substance prescriptions have their own required elements: the physician’s name, address, and license number, a handwritten signature, a barcode issued by the Ministry of Health, the patient’s name and address, the diagnosis, the drug’s dosage and presentation, and the number of days prescribed. Narcotic and psychotropic prescriptions are capped at 30 days of therapy per prescription.
The barcode matters. Physicians have to register with COFEPRIS and receive assigned barcode numbers before they can prescribe controlled drugs at all. Not every doctor you can book will have that authorization. Confirm before the appointment, or the visit will not produce a fillable prescription. Pharmacies will refuse a controlled-substance prescription that is missing any of the required elements.
Bringing Codeine Back Into the United States
The return trip is a separate customs event. U.S. Customs and Border Protection requires you to declare medication containing potentially addictive substances, carry it in original containers, and bring only a personal-use quantity.6U.S. Customs and Border Protection. Traveling with Medication to the United States
With a valid prescription from a U.S.-licensed practitioner registered with the DEA, you can bring back more than 50 dosage units of a controlled substance. Without a U.S. prescription, the ceiling is 50 dosage units, and only substances that can legally be prescribed in the United States qualify.6U.S. Customs and Border Protection. Traveling with Medication to the United States Codeine qualifies. A written statement from your physician confirming the medication is medically necessary and taken under supervision strengthens your case at the U.S. border, especially if you filled the prescription in Mexico.