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 said. “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 US.
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 US, with the remaining product from China.
While 5-HTP is popular in the US, 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 could support 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 said that 5-HTP could cause side effects such as a temporary increase or decrease in blood pressure, gastrointestinal disorders, 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 the other ingredients commonly found in height growth supplements flagged by the MFDS. Products containing these ingredients have originated from Japan.
Restricted ingredients found in cognitive health products
On the other hand, Bacopa, deanol, and L-dopa were the key ingredients found in the 18 cognitive health products flagged by the MFDS.
Bacopa, a botanical ingredient, came under the spotlight in April due to concerns around side effects such as nausea, abdominal pain and increased bowel movements.
The MFDS said that Bacopa-containing supplements that were flagged out this time round came from the US and Germany.
L-dopa, while being used as a bioactive in supplements for focus and mood, is classified as a prescription drug for Parkinson disease in South Korea.
The ministry added that it is associated with side effects such as dizziness, headache, drowsiness, nausea and nerve cell damage. In its investigation, the MFDS said that supplements containing L-dopa came from the US, Japan and Canada.
Deanol, or 2-(dimethylamino)ethanol, on the other hand, is associated with side effects such as sleep disorders, headache and gastrointestinal problems.
