Mexico said Friday it is already seeing black market or fake versions of molnupiravir circulating for sale, just one week after authorities approved the drug to treat those at risk of severe COVID-19.

The real medication is produced by U.S. pharmaceutical company Merck. But Mexico’s health regulatory agency found versions labelled molnupiravir for sale from an array of companies like “Merit,” “Molaz” and “Azista.”

The agency said Friday that it had no record of any permits for import or sales of those companies’ drugs and considered them a health risk.

The Federal Commission for Health Protection wrote that, because molnupiravir is approved only for prescription use, “any product advertised as over-the-counter molnupiravir should be considered a health risk because of its dubious origin.”

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Mexico's government approved molnupiravir from Merck for use last week for adults with COVID-19 and “a high risk of complications.” On Friday the agency approved a second pill, Paxlovid, from Pfizer, for use on adult patients “at risk for complications.”

Mexico has long been plagued by counterfeit medicines, corruption within the regulatory agency, and a penchant for self-medication due to the country's inadequate health care infrastructure.

The country has seen coronavirus cases spike by over 200% in the last week, apparently due to the omicron variant, and faces a shortage of tests, which tends to drive consumers toward the black market.

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Mexico does so little testing that, while test-confirmed COVID-19 deaths hover around 300,000, a government review of death certificates places the real toll at around 460,000.