It is a famous product of Hong Kong, produced at the Po Sum On Medicine Factory. The company was established in 1907 specifically to produce this oil. Po Sum On.
Po Sum On is made by steam distillation of the herbs, and contains no synthetic ingredients. The oil is comprised of the following ingredients per 100 ml (the standard bottle is one ounce, about 30 ml):
Peppermint oil 57.30 ml
Tea oil 38.77 ml
Dragon blood 2.07ml
Cinnamon oil 0.96 ml
Scute 0.58 ml
Licorice 0.32 ml
Po Sum On is a warming liniment for the circulation, yet it has an anti-inflammatory effect for the skin. IPo Sum On is used to treat joint and muscle aches, used for osteoarthritis, neuralgia, and traumatic injuries (sprains).