A man walks out of a pharmacy in Seoul on July 10. (Im Se-jun/The Korea Herald) Travelers can bring certain controlled medications into South Korea for personal treatment, but they must obtain approval from the Ministry of Food and Drug Safety before entering the country.This can apply to some medicines commonly prescribed or sold over the counter overseas.South Korea strictly regulates narcotics, psychotropic substances and other controlled drugs, including some ingredients found in medicines widely used in other countries.One example is dextromethorphan, an ingredient found in some versions of the US cold medicine DayQuil. Dextromethorphan is classified as a psychotropic substance under Korean law.Travelers should therefore check whether any ingredient in their medication is classified as a controlled substance in Korea before packing it for a trip.Korea does, however, allow travelers to bring narcotic or psychotropic medications for personal treatment if they receive the required approval.Applying for permissionAnyone entering Korea with medication containing a controlled narcotic or psychotropic substance for personal treatment must receive approval from the Ministry of Food and Drug Safety, regardless of nationality.The requirement has been in place since 2009. Since Dec. 27, 2024, travelers have also been able to apply online through the ministry's Drug Safety Korea website.Search "Nedrug Korea" to find Drug Safety Korea, or "Uiyakpum Anjeon Nara" in Korean.On the Korean-language version of the website, go to the E-Civil Service Application/Report section and select "Permit to Bring in Narcotics for Self-Treatment."The application service itself is only available through the Korean version of the site, but English translations are provided for individual fields within the application process.Applicants can log in using email verification.They are then asked to provide personal information, details of their stay in Korea and information about the medication, including its name, active ingredient, dosage and quantity.Applicants must also state the purpose for carrying the medication and the medical condition for which it was prescribed.Supporting documents may include a copy of the applicant's passport, documents concerning their stay in Korea, a valid prescription and medical documentation showing the need for the medication. Depending on the drug and the applicant's circumstances, additional documentation may be required.Once submitted, applicants can use the website to check their application status and see whether the MFDS has requested additional information.The MFDS provides a user manual for the process in Korean, English, Japanese, Chinese, French and Spanish. The manuals are available on the MFDS information page and through the online application login page.How long approval takesTravelers should apply well before their planned arrival in Korea.MFDS guidance has generally advised applicants to allow up to 10 business days for review, although processing may vary depending on the medication and whether additional documents are required.Travelers should not assume that a prescription from a doctor overseas automatically makes a controlled medication legal to bring into Korea.Rules for cannabis-based medicationCannabis and cannabis-derived substances are subject to particularly strict controls in South Korea.Korean law does provide limited pathways for patients to obtain certain cannabis-based or other controlled medicines for medical treatment, particularly when no domestic alternative is available.Such cases can involve additional approval procedures and, in some circumstances, the Korea Orphan & Essential Drug Center.This does not mean that any cannabis product prescribed or legally purchased overseas can be brought into Korea. Products that are legal for medical or recreational use in another country may still be prohibited under Korean law.Travelers carrying cannabis-based medication should therefore confirm its legal status and obtain any necessary authorization before entering Korea.Key points for travelersThe key is to check the medication's ingredients, not simply whether it was legally prescribed or sold over the counter in another country.Korea's list of controlled substances includes ingredients that travelers may not regard as unusual or dangerous at home.If a medication contains a narcotic or psychotropic substance that is regulated in Korea, travelers may need MFDS approval before bringing it into the country.Violations of Korea's drug laws can carry criminal penalties, and foreign nationals convicted of offenses may also face immigration consequences, including deportation or restrictions on reentry.