Moxa - how to assess its quality?
There are many different types of moxa available on the market, coming from various manufacturers. As customers and therapists, how can we evaluate the quality of individual moxa products and choose the one that works best for moxibustion treatments? A team of Chinese researchers led by Wu Juan has classified moxa into three quality categories. Learn how to identify the one with the highest quality and therapeutic effectiveness.
Table of Contents:
1) The impact of the moxa production process on its quality
2) How long should moxa mature?
3) Moxa maturation and its effectiveness
4) How to recognize high-quality moxa?
5) Three quality classes of moxa
6) The source of raw materials for moxa production
The impact of the moxa production process on its quality
Old moxa is made from mugwort leaves that have been stored for at least one year. If moxa is made from mugwort leaves that have been stored for three years, it is called three-year moxa. Moxa producers offer moxa products with labeled storage time which is from one year to ten year.
There are always controversies among producers of moxa. The storage environment of dried mugwort leaves affects the quality of moxa. Bundles of dried mugwort leaves are stacked in a storehouse which should be damp proof and fire proof. Long-time storage means higher costs with higher risks of mildew, decay, oxidation and moth damage. Therefore, the more years the storage of mugwort leaves has been, the higher price moxa has. It is unavoidable that some products are labeled with false information.
How long should moxa mature?
According to the research of Qi Shuguang, mugwort leaves that have been stored for more years have fewer volatile constituents. The burning speed of one-year moxa is higher than that of three-year moxa and five-year moxa. One-year moxa has the highest speed of heating the skin, while three-year moxa has a higher speed than five-year moxa. The fire of five-year moxa is gentle but has strong penetrability. Comparing with one-year moxa and three-year moxa, patients feel more comfortable and acceptable when using five-year moxa for moxibustion.[1]
According to the research of Wang Xiaoping and his team for infrared spectrum characteristics of moxa sticks with five different storage years (1, 2, 3, 5 and 7 years), the infrared intensity of five-year moxa is highest, the next is that of three-year moxa. The infrared intensity of five-year moxa and three-year moxa is significantly higher than that of one-year moxa and seven-year moxa. The research shows the heat of combustion of one-year moxa and two-year moxa is lower than that of three-year moxa and five-year moxa, but the heat of combustion of seven-year moxa is lower than that of one-year moxa and two-year moxa. The research also shows that the smoke of one-year moxa has the highest level of harmful free radicals. Based on the research, moxa made from mugwort leaves that have been stored for three to five years are preferred.[2]
However, though Qi Shuguang and Wang Xiaoping both recommend five-year moxa, Qi Shuguang’s research shows one-year moxa has higher heat of combustion than five-year moxa, while Wang Xiaoping’s research shows one-year moxa has lower heat of combustion. The research of Wu Juan and her team also got conflicting data when comparing heat of combustion of moxa with different sources and different storage years. In the opinion of Wu Juan, there is no final conclusion about the influence of storage years of mugwort leaves on heat of combustion of moxa.[3]
Moxa maturation and its effectiveness
The research of Xue Shiyong and his team shows that both one-year moxa and three-year moxa can improve the pain, stiffness and motor function in patients with moderate-to-severe knee osteoarthritis, while three-year moxa has better therapeutic efficacy in improving stiffness of the knee joint than one-year moxa.[4]
How to recognize high-quality moxa?
Based on the mentioned researches, three-year moxa or five-year moxa is obviously a better choice for moxibustion therapists. You don’t have to concern too much about the purity of moxa or a leaf-moxa ratio. But you may roughly distinguish the quality of moxa through its color and texture.
Three quality classes of moxa
After investigating 47 moxa samples, Wu Juan and her team classify moxa as three grades.[5]
The first grade has the best quality. With the first grade, the color of moxa is grayish yellow, light brownish yellow or khaki. The moxa may have a lot of black or green black tiny fragments of leaves. The moxa is light and very soft. Your fingers don’t feel rough when kneading it. The moxa has slight herbal fragrance.
The second grade of moxa is grayish yellow or dark yellow, sometimes with slightly dark green color. The moxa may have lots of black or green black tiny fragments of leaves. Occasionally or rarely you may see pale yellow coarse fibers and pale coarse particles. When kneading the moxa, your fingers may feel rough but there is no prickle. The moxa has herbal fragrance.
The third grade has the lowest quality. With the third grade, the color of moxa is dark green yellow, sometimes with grayish green color. There are a large number of black or green black tiny fragments of leaves. Sometimes you may see pale yellow or greenish yellow coarse fibers and pale coarse particles. When kneading the moxa, fingers feel very tough and sometimes there is prickle. The moxa may have strong herbal fragrance, or its herbal fragrance is light but very special.
The source of raw materials for moxa production
As for the origin of raw material used by Chinese moxa producers, nowadays high-quality mugwort leaves are mainly from Qichun of Hubei or Nanyang of Henan, and sometimes you may see raw material from Suizhou of Hubei or other areas.[6]
References:
[1] QI Shuguang. Study on Difference of Physical and Chemical Effects of Qi Moxa with Different Storage Years. Wanfang Data; 2011.
[2] WANG Xiaoping, SHEN Xueyong, WEI Jianzi. Study on the Spectral Characteristics of Infrared Radiation of Mild Moxa-stick Moxibustion with Different Parameters. Shanghai Journal of Acupuncture-Moxibustion. 2021; 40 (3): 358 - 361.
[3] WU Juan, WAN Dingrong, JIANG Yuanming, et al. Determination of Combustion Heat Value of Raw Material Moxa for Moxibustion Therapy. Shanghai Journal of Acupuncture-Moxibustion. 2020; 39 (12): 1623 - 1627.
[4] XUE Shiyong, WANG Chunyan, LI Tao, et al. Therapeutic Efficacy Observation on Moxibustion with Moxa of Different Storage Years for Moderate-to-severe Primary Knee Osteoarthritis. Journal of Acupuncture and Tuina Science. 2020; 18 (5): 345 - 351.
[5] WU Juan, WAN Dingrong, ZHAO Baixiao, et al. Quality Evaluation Standard and Commodity Classification of Moxa. China Pharmaceuticals. 2019; 28 (24): 4 - 7.
[6] SUN Yu, LI Jiping, WU Jingyi, et al. Suggestions for Quality Research on Moxa Stick. Chinese Journal of New Drugs. 2019; 28 (9): 1044 - 1047