▲ Cocaine loaded at a container entrance
South Korea, once referred to as a drug-free country, is now seeing more than 10 new types of illicit drugs emerge every year.
These substances are either modified versions of the chemical structures of existing drugs or new substances introduced into the country from abroad.
The National Forensic Service (NFS), the largest drug analysis agency in the country, is responding swiftly. However, public anxiety over so-called stealth drugs has grown recently as videos suspected of involving drug use have spread across social media, even before their authenticity could be confirmed.
Stealth drugs refer to new types of drugs with altered chemical structures designed to evade detection by standard preliminary drug screening tests used by law enforcement agencies.
According to the 2025 Drug Analysis White Paper published by the NFS today (July 8), 11 new types of drugs were identified in the country last year.
The number of new drugs discovered, which stood at 6 in 2021 and 7 in 2022, surged to 10 in 2023 and 15 in 2024, nearly doubling.
This means 49 types of new drugs have emerged over the past five years.
One such case involved a plastic bag containing white powder found buried in a flower bed behind an apartment complex in Cheonan, South Chungcheong Province, in January of last year.
NFS analysis confirmed the powder to be 2-fluoro-2-oxo-PCP, a new type of phencyclidine.
As it was a new drug not previously reported domestically or internationally and was not registered in the domestic drug database, it was reportedly marketed among drug offenders as a stealth drug that cannot be detected.
Through precise analysis, the NFS classified the drug as a psychotropic substance falling under phencyclidine analogs according to the Narcotics Control Act.
The NFS explained, "As it was a substance never before reported globally, we analyzed its structure using techniques such as liquid chromatography-quadrupole time-of-flight mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy to identify its structure and report it for the first time in the world."
New drugs do not only refer to newly manufactured substances.
Even if a substance has already been circulating overseas, it becomes a new subject for analysis once it is identified in Korea for the first time.
Furthermore, because new substances can be created by slightly altering the chemical structure of existing drugs, analysis agencies must establish appropriate testing methods whenever a new component is identified.
Along with the spread of new drugs, the number of drug analysis requests received by the NFS has increased 3.2 times over the past seven years, from 43,808 in 2018 to 140,775 last year.
In particular, looking at drugs detected in seized items submitted to the Seoul Institute of Forensic Science, the proportion of new drugs such as synthetic cannabinoids and ketamine surged from less than 10% in 2020 to over 30% in 2025.
The NFS explained that as the number of new drugs that are difficult to detect with existing primary preliminary tests increases, cases of immediately proceeding to secondary precise analysis are also rising.
Once a new substance is identified, the NFS analyzes its chemical structure and requests the Ministry of Food and Drug Safety to designate it as a temporary controlled substance, based on which it establishes targets for analysis and testing methods.
Kim Dae-gyu, head of the Korea Drug Prevention Education Research Institute (former chief of the drug crime investigation unit at the Gyeongnam Provincial Police Agency), who investigated the drug kingpin Park Wang-yeol, said, "If it is a new substance not yet identified in the country, we cannot rule out the possibility that it may be difficult to immediately identify it within the existing testing system."
Kim emphasized that as trade via social media and individual imports from abroad increase, the borders for drugs have effectively collapsed, and as new drugs continue to emerge, analytical capabilities and testing systems must be continuously upgraded accordingly.
The misuse and abuse of psychotropic drugs prescribed in medical settings is also a factor increasing the workload of the NFS.
The NFS analyzed that "the abuse of anesthetics, continuing from propofol and etomidate to medetomidine, shows that the demand for anesthetics persists, with only the substances changing."
It further explained, "While the Narcotics Control Act is striving to bring all medical anesthetics under legal regulation, debates with the medical community over the convenience of therapeutic application have delayed their inclusion as regulated substances."
Recently, a video suspected of involving drug use in Suwon has circulated, leading to claims among citizens that it might involve new drugs.
This arose because a man in his 30s in the video tested positive for methamphetamine in a preliminary police drug test, but tested negative in a detailed urine analysis by the NFS.
However, a police official stated, "It is difficult to give a definitive answer as there is a possibility that drugs could be detected through the ongoing detailed hair analysis," adding, "At the current stage of the investigation, no evidence of so-called stealth drugs has been confirmed."
Typically, hair analysis can confirm drug use over the past 3 to 6 months, while urine analysis can detect use within the past week.
Experts note that results from preliminary tests and precise analyses can differ.
This is because preliminary tests can show cross-reactivity, where they react to legal drugs with similar structures.
Positive results can occur even if a person has taken cold medicine or certain other medications, and it was found that the man in the Suwon video was also taking medication.
In a similar case, a taxi driver who caused a multi-vehicle accident near Jonggak Station in Seoul early this year tested positive for morphine in a preliminary drug test immediately after the accident.
However, no drug components were detected in the NFS precise analysis.
The driver stated that he had taken cold medicine while exhausted from overwork.
Jeong Hee-sun, a chair professor at the Department of Forensic Science at Sungkyunkwan University who served as the head of the NFS, explained, "Preliminary tests are meaningful for screening out people who have not used drugs, but one cannot conclude that a person has used drugs just because they tested positive," adding, "It must be confirmed through precise testing."
(Photo: Provided by Korea Customs Service, Yonhap News)
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