Emperor Minh Mang (明命), the second ruler of the Nguyen Dynasty in Vietnam, reigned from 1820 to 1841. He is widely regarded by contemporary historians as the most distinguished monarch of his dynasty, despite some controversial policies. One aspect of his extraordinary legacy is the remarkable 142 offspring he sired - 78 princes and 64 princesses - earning him the unprecedented distinction of having the most progeny among kings in world history. Vietnamese people suppose Minh Mang's prolific reproductive success to the consumption of a specially prescribed medicine known as Minh Mang Thang (明命湯, MMT). This medicine, often associated with sexual potency and fertility, is characterized by intriguing names such as "One night Five sexes," "One night Six sexes born Five babies," or "Six sexes Three pregnancies." Vietnamese folklore vividly recounts Minh Mang's exceptional sexual prowess, attributing it to the use of MMT. MMT formulations, which include various herbs, notably Korean ginseng, may incorporate additional botanical ingredients depending on their intended purpose. This paper aims to explore the origins, history, ingredients, and applications of MMT, unraveling the mystery behind this mystical prescription that has inspired several oriental medicinal researchers. Through this investigation, we seek to shed light on the cultural and historical contexts surrounding Minh Mang's use of MMT and its enduring impact on traditional Vietnamese medicine and folklore.

Keywords: Vietnamese Traditional Medicine, Minh Mang Thang, Korean ginseng, Mystical prescription