North Korea claims to have succeeded where the greatest minds in science have failed by producing a drug which can prevent and cure Mers, Ebola, Sars and Aids.
The authoritarian, impoverished nation better known for pursuing a nuclear programme has provoked widespread scepticism following the announcement.
The official Korean Central News Agency said scientists had developed Kumdang-2 from ginseng and other ingredients.
North Korea trumpeted the same drug during deadly bird flu outbreaks in 2006 and 2013.
The North's claim comes as rival South Korea fights an outbreak of Mers that has killed two dozen people and sickened more than 160 since last month.
There is no known vaccine for the disease.