[Reuters/Yonhap]
[Reuters/Yonhap]

As interest in obesity treatments grows, a rising number of South Koreans are traveling to Japan to obtain prescriptions for Mounjaro — a diabetes drug — at significantly lower prices, according to local media reports. Information about Japanese clinics offering cheaper prescriptions is being shared across South Korean online communities and SNS platforms, with some hospitals earning the informal label of "pilgrimage sites" for the drug.

Nagoya TV and other Japanese outlets reported that South Koreans have been visiting Japan in increasing numbers to obtain Mounjaro prescriptions. Mounjaro is an injectable drug containing tirzepatide, developed by US pharmaceutical company Eli Lilly, and is approved in Japan as a treatment for type 2 diabetes.

A woman in her 30s from Seoul told Nagoya TV that she had traveled to a regional hospital in Japan to get a Mounjaro prescription. "I went because it was known as the cheapest hospital in all of Japan," she said.

She added that when she visited the clinic, she saw several other middle-aged Korean women also there to receive Mounjaro prescriptions.

Price is cited as the primary reason South Koreans are making the trip to Japan.

The woman said the cost of a three-month supply of Mounjaro 5 mg in South Korea exceeds what she paid in Japan for the same supply — even after covering airfare and accommodation.

Information about Japanese medical facilities offering Mounjaro at relatively low prices is being actively shared on South Korean SNS platforms and online communities. Japanese media reported that not only hospitals in major cities such as Tokyo and Osaka, but also lesser-known regional clinics, are being introduced among Koreans as "Mounjaro pilgrimage sites."

Japan's "free medical practice" system is what makes such prescriptions possible.

Although Mounjaro is approved in Japan only for type 2 diabetes, doctors may prescribe it for unapproved indications based on their assessment of a patient's condition — a practice known as off-label prescribing. When prescribed for cosmetic or weight-loss purposes, national health insurance does not apply and patients bear the full cost themselves.

The number of medical facilities offering prescriptions through online consultations has also grown, making the drug more accessible.

Japanese authorities, however, have repeatedly warned against the spread of Mounjaro use for weight-loss purposes.

Japan's Ministry of Health, Labour and Welfare has cautioned that the safety and efficacy of GLP-1 receptor agonists and GIP/GLP-1 receptor agonists — including Mounjaro — for cosmetic or weight-loss purposes have not been verified in Japan for those uses. In June, the ministry reissued a notice urging medical institutions and manufacturers to promote appropriate use.

Peer-to-peer sales of prescription drugs through SNS or secondhand trading platforms are also illegal in Japan. The ministry warned that products obtained through channels other than licensed medical institutions or pharmacies may include counterfeit or substandard items.

The manufacturer has also expressed concern about rising overseas demand driven by Japan's lower prices.

Eli Lilly Japan said last month that Mounjaro's price in Japan is among the lowest of any major economy in the world, and that the low price risks encouraging inappropriate use, medical tourism from abroad, and profit-driven stockpiling and resale overseas.

Even for those who obtain a prescription in Japan, bringing the medication back to South Korea requires additional care.

South Korean customs authorities detected 289 cases of Mounjaro and similar drugs being brought into Incheon airport without proper procedures between January and May this year, Nagoya TV reported. Even when a drug is legitimately prescribed abroad, relevant regulations may apply to its importation into South Korea depending on the type and quantity of the medication.

Post-treatment medical follow-up is another concern. Tirzepatide requires ongoing consultation with a physician to adjust dosage based on the patient's condition and any side effects. Obtaining a one-time prescription in Japan and returning home may make it difficult to continue monitoring with the prescribing doctor.

A Japanese pharmaceutical expert told a local broadcaster that the drug is "fundamentally one that should be used while consulting with the prescribing doctor to adjust the dosage," and warned that cutting off medical supervision after crossing a border to obtain the drug could pose serious risks if side effects occur.

As South Koreans' Mounjaro trips emerge as a new medical tourism phenomenon driven by price differences, the Japanese government is tightening oversight of off-label use and potential supply shortages. Experts say those considering overseas prescriptions should weigh not only the lower cost but also the drug's intended use, potential side effects, domestic import regulations, and the feasibility of ongoing medical care.


rainbow@heraldcorp.com