My understanding of Mexican Rx laws comes (to a major degree) from what is posted on website of the Secretary of Health for the Republic of Mexico. Also from the warning printed on the package stating that a Rx is required to purchase Viagra.
(Some say the package is generic and thus contains the warning. However, if the package contains a SSA number, the name of a Mexican distribution company, etc. then the package is specific to Mexico and not generic. Most pharmacies will also say that a Rx isn’t required, but technically it is that record keeping isn’t required. [Do you really think pharmacies would say a Rx is required and risk losing business? Especially when the law is almost never enforced.])
Here is (in part)
what is posted by the Secretary of Heath on his website.
NORMA Oficial Mexicana NOM-072-SSA1-1993, Etiquetado de medicamentos.
5.11.1 En la etiqueta de los medicamentos, se deberل ¥xpresar la clave de registro sanitario, tal como se indica en el oficio de registro, seguida del n? romano de la fracciَ® ±ue corresponda a los medicamentos, ambos con la misma tipografي، y tamaٌ¯ y de acuerdo a la siguiente clasificaciَ®؛
I. Medicamentos que sَ¯ pueden adquirirse con receta o permiso especial, expedido por la Secretarي، de Salud;
II. Medicamentos que requieren para su adquisici eceta m餩ca que deberل ²etenerse en la farmacia que la surta y ser registrada en los libros de control que al efecto se lleven;
III. Medicamentos que sَ¯ puedan adquirirse con receta m餩ca que se podrل ³urtir hasta tres veces;
IV. Medicamentos que para adquirirse requieren receta m餩ca, pero que pueden resurtirse tantas veces como lo indique el m餩co que lo prescriba;
V. Medicamentos sin receta, autorizados para su venta exclusivamente en farmacias, y
VI. Medicamentos que para adquirirse no requieren receta m餩ca y que puedan expenderse en otros establecimientos que no sean farmacias.
Medications fall into one of several categories:
Category I medications may only be taken with permission of the Secretary of Health. Usually they are experimental drugs.
Category II drugs require the pharmacy to keep records on who bought the medication. The pharmacy will keep your Rx and you will need a new Rx each time you visit the pharmacy.
Category III medications are limited to three refills. Records should be kept by the pharmacy and the Rx stamped each time it is filled.
Category IV medications require an Rx from a Mexican physician. However, the pharmacy is not required to keep records about who bought the medication.
Category V medications do not require an Rx. They can only be sold in a pharmacy.
Category VI medications do not require an Rx. Their sale in not restricted to a pharmacy (think of something like Aspirin sold in grocery stores).
Category III medications are controlled substances that are normally habit forming. (Think of something like vicodin or oxycontin.) Possession of Category III medications is a serious offense and may result in prison time.
Most prescription medications--including Viagra, Cialis, and Levitra--are Category IV medication. (Cialis's registration number, for example, is 181M2002 SSA IV.) The regulation above says these medications require a prescription from a Mexican physician and that it can be refilled as many times as the doctor indicates. Since record keeping by the pharmacy is not required for Category IV medications many people and pharmacies say an Rx is not required. While this is correct in practice, it is technically not correct legally.
In contrast to Category III medications, the penalty for having Category IV medications without a Rx is a minor fine. (I think that’s the 452.40 to 357.20 peso fine for “Activities related to drugs or prostitution” on the
Muncipality of Tijuana website.
In many Latin American countries so many people lack money to visit physicians that pharmacists often provide medical care. Hence laws requiring a Rx are seldom enforced, especially since the real goal is to stop medications from being sold in swap meets and by those with no understanding of pharmacology. However, the law is on the books and an "enterprising cop" can use it to extort money. Unfortunately, the cops in Tijuana have “found” this law used it to shakedown tourists.
My best guess, however, is that if you refused to pay a bribe in the event the cops find you in possession of Viagra without a Rx they’d let you go. They wouldn’t make any money arresting you. Plus because the law is universally ignored I don’t know what a judge would do—he might let you go or at worst give you a small fine.
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When I was a kid some "hippies" set up a commune in a small farming town. The local farmers didn’t like them and wanted the cops to "do something." One night when the "hippies" drove into town the local cops arrested them. Their crime was violating an old "horseless carriage" law that required somebody with a lantern to walk 100 feet ahead of a motorized vehicle warning all of it approach.
It’s the same thing with the Rx requirement for Category IV medication. It’s a law everybody ignores. Any pharmacy will sell you Viagra without a Rx.
However, the law is on the books. The cops have found this law and are using it to extort money from tourists they catch in possession of Viagra. (Which is why I advise guys to take Viagra before leaving the pharmacy or get a Rx if they are going to wander around the streets carrying Viagra.)