Zhang Nao, Camphor, Cinnamomum Camphora Increases local circulation and relieves pain. Camphor is a natural product derived from the wood of the camphor Laurel Tree (Cinnamomum camphora L.) It increases circulation and relieves pain. The trees that Camphor is derived from are 50 years old. First, the camphor laurel tree’s wood is steamed or roasted. Then those vapors are caught and condensed to capture the volatile oils. Zhang Nao is highly graded, medical quality camphor and a key ingredient Zheng Xie Gu Shui. Genuine, medicinal-grade, natural Camphor only comes from trees that grow in Southeast Asia. Other regions cannot grow trees with enough medicine to make harvesting for Camphor worthwhile. The synthetic version of Camphor is made from the stumps of the southern pine tree. It is produced through a chemical process similar to turpentine. However, the difference between synthetic and natural Camphor is striking. While natural turpentine oil from southern pine trees has some healing properties, it is unsafe to use directly on the skin. Unfortunately, synthetic Camphor became popular because it is less expensive to produce. In addition, Southern Pine trees are more abundant than Camphor Laurel trees, making it possible to produce larger quantities of synthetic Camphor. Fun Fact About Synthetic Camphor In WWII, Camphor was used in the U.S. as a critical component in insect repellant. The prices for natural Camphor skyrocketed since the commodity was only produced in Southeast Asia. The demand was so high its value exceeded that of gold! However, scientists in America found a way to synthesize Camphor from the Southern Pine Tree stump, the same tree that produces medicinal-grade turpentine oil. To this day, the discovery of synthesis is the only thing that keeps Zhang Nao’s prices regulated!