The ministry, together with the Korea Consumer Agency (KCA), conducted a joint investigation of 60 health supplements claiming to support height growth and cognitive function—two categories of supplements popular among students. These supplements were bought online.
Of these, 37 products, including those from major international brands, were found to contain ingredients not permitted for use in food and health supplements in South Korea.
The MFDS said it has since initiated customs holds, sales-blocking measures and administrative sanctions to prevent these products from entering the Korean market.
“This investigation was conducted ahead of the College Scholastic Ability Test (CSAT) to protect consumers—who are often highly concerned about their children’s academic performance and physical health—from potential harm,” the MFDS stated. “The Korea Consumer Agency purchased the products for testing, while the Ministry of Food and Drug Safety conducted the analysis to determine whether any hazardous ingredients were present or declared on the labels.”
Information on these products was also added to South Korea’s food safety database, which specifies products containing ingredients not permitted for use in food supplements.
As of Nov. 5, a total of 5,080 products can be found in the database, with the majority—over 3,000—from the United States.
5-HTP common in height growth products
5-Hydroxytryptophan (5-HTP) was one of the most common ingredients used in these supplements, specifically those marketed for height growth.
Thirteen out of 19 height growth supplements claimed to contain 5-HTP, and all except one originated from the United States, with the remaining product from China.
While 5-HTP is popular in the United States, especially as a sleep aid ingredient or for stress relief, menstrual and hormonal support, it is not allowed in food supplements in South Korea.
Research has shown that 5-HTP plays a major role in neurological and metabolic diseases and may help address serotonin depletion. Separately, a study from Singapore reported that it could be used as a complementary supplement to promote cognitive function and mental health in the aging population.
The MFDS reported that 5-HTP may cause side effects including temporary increases or decreases in blood pressure, gastrointestinal disturbances, vomiting and diarrhea.
L-citrulline, which is regulated as an OTC drug in South Korea, and dolomite, which is not permitted for use in food, were also commonly identified ingredients in height-growth supplements flagged by the MFDS. Products containing these ingredients were primarily sources from Japan.
Restricted ingredients found in cognitive health products
Bacopa, deanol and L-dopa were the key ingredients found in the 18 cognitive health products flagged by the MFDS.
Bacopa, a botanical ingredient, also attracted attention in April due following concerns about potential side effects such as nausea, abdominal pain and increased bowel movements.
Acoording to the MFDS, bacopa-containing supplements flagged in the latest round came from the United States and Germany.
L-dopa, while used as a bioactive in supplements for focus and mood, is classified as a prescription drug for Parkinson’s disease in South Korea.
The ministry also noted that it has been associated with side effects such as dizziness, headache, drowsiness, nausea and nerve cell damage. Supplements containing L-dopa originated from the United States, Japan and Canada.
Another ingredient of concern was deanol, or 2-(dimethylamino)ethanol, which has been linked to side effects such as sleep disorders, headache and gastrointestinal problems.