Janssen Korea’s Concerta supply strained amid soaring ADHD prescriptions and tighter controls

A shortage of Concerta (methylphenidate), a medication widely used to treat attention deficit hyperactivity disorder (ADHD), has raised concerns in Korea, as patients and doctors navigate limited supply and regulatory changes that could further impact access.

Janssen Korea, the importer of Concerta, confirmed the supply issue on Tuesday, attributing it to global production constraints, increasing demand, and regulatory delays in multiple countries. 

The shortage, which began with the 36-milligram dosage in November before extending to the 54-milligram and 18-milligram strengths in December and January, has coincided with tighter government oversight of ADHD medications, prompting questions about whether new restrictions are exacerbating supply challenges.

While Janssen Korea insists the shortage is "unrelated to safety or quality concerns," its timing has drawn scrutiny. 

In July 2024, the Ministry of Food and Drug Safety (MFDS) launched stricter monitoring of methylphenidate-based drugs, citing concerns over misuse. For two weeks following the announcement, the agency conducted inspections at 60 medical institutions with high prescription rates and implemented a tracking system for medical narcotics following reports of theft and improper distribution.

Korea has seen a sharp rise in ADHD diagnoses and prescriptions. In 2023, the number of patients prescribed methylphenidate increased by 26.7 percent, reaching 280,663. MFDS data showed that the largest increases were among teenagers and young adults, groups that have also been at the center of concerns about non-medical use of ADHD medications as cognitive enhancers.

Despite speculation that regulatory tightening may be linked to supply shortages, officials say there is no direct evidence of a connection. "It is difficult to conclude that misuse has led to supply disruptions," an MFDS official said. "As a prescription drug, its distribution is strictly controlled by doctors, and we have systems in place to monitor and manage supply."

Concerta, a long-acting stimulant designed for 12-hour release, is one of 13 methylphenidate-based ADHD medications approved in Korea and produced by three companies. Myung In Pharm, which manufactures Medikinet Retard Cap and Perospin tablets in various dosages, has not announced plans to ramp up production. Whan In Pharm, the other domestic supplier and producer of Penid Tab, declined to comment on whether it would take steps to ease the shortage.

Janssen Korea has not provided a timeline for when supply will return to normal. "We can’t speculate when supply will be restored due to the unpredictability of the market and general increased demand," a company official said. "In the interim, patients who are prescribed branded Concerta where supply is unavailable should speak with their healthcare provider about an interim treatment plan.

The supply crunch comes as Korea prepares for new regulatory changes set to take effect in June, which could make access to ADHD medications even more restrictive. In January, the MFDS announced plans to tighten prescribing rules for medical narcotics, including ADHD treatments, and to enhance oversight of online and overseas purchases using artificial intelligence monitoring tools.