The first capsules containing human flesh were found by South Korean customs officers last August.
Since then they say the number being smuggled in from China has been rising.
Some Chinese workers and cancer patients in South Korea take the supplement believing its human foetus content boosts stamina.
But scientists in Incheon say there's every sign they also contain dangerous micro-organisms.
SOUNDBITE: SHIN EUL-GI, INCHEON AIRPORT CUSTOMS INSPECTION LABORATORY OFFICIAL, SAYING (Korean):
"Super-bacteria and other viruses and bacteria which are harmful to the human body are detected in them."
South Korean customs authorities believe the pills are produced in northeastern areas of China from dead human foetuses.
They say they're tightening up checks on drugs from China to stem the flow of such supplements coming into the country.
Paul Chapman, Reuters