The discussion about the dosage of asarum was first seen in Song Dynasty. Chen Cheng's "Materia Medica Needless to Say" said, "If Asarum is used alone, it cannot be used for more than half a text. If you use it many times, you will suffocate and the loser will die. " A penny is equivalent to 1.5 to 2 grams, and a half penny is not more than 1 gram. Later, it was widely circulated in Li Mingshizhen's Compendium of Materia Medica, which quoted "Needless to say, Materia Medica" and said: Asarum, if used alone, can't spend too much money. If it is too much, you will suffocate. He described one and a half dollars as a dollar, which seems to be bigger than that in Don't Say (a dollar in ancient times is equivalent to about 3 grams today). However, due to the great influence of Compendium of Materia Medica, doctors in later generations passed on the wrong words, and did not specify "if it is used alone". Until now, both decoction powder and compound prescription have said "no cost".

Modern pharmacological research shows that Asarum mainly contains volatile oil, and the effective components in the oil are methyl eugenol (about 50%), safrole (10%) and elemene, and the toxic component is safrole. The volatile oil of asarum has an exciting effect on frogs, mice and rabbits. At first, it was, then it was paralyzed, gradually reducing voluntary movement and respiratory movement, disappearing at the same time, and finally died of respiratory paralysis. Breathing stops before heartbeat, which has a direct inhibitory effect on myocardium and smooth muscle. The ethanol extract of rabbits can antagonize the respiratory depression caused by morphine. The LD50 of mice were 123.75 mg and 7.78 mg/10 g, respectively. The alcohol extract of asarum is more toxic than the decoction. Therefore, it is in line with "many people suffocate, and those who fail to pass die."

So why use a large dose of decoction in clinic? It turns out that after Asari was decocted at high temperature for 30 minutes, the safrole in the volatile oil was only 2% of the original medicinal material. Therefore, if the powder is effective with 1 g, the decoction is effective with 50 g after 30 minutes of decoction. If you don't spend too much money, it won't even scratch your boots. In addition, the varieties of asarum are quite different from traditional varieties. The traditional species should be China Asarum, and the similar species are North Asarum (Liaodong Asarum) and Seoul Asarum, both of which are authentic medicinal asarum recorded in China Pharmacopoeia. Now in some places, asarum (other than the genuine asarum) is used instead of the genuine asarum, and the effect is even more discounted.

The results showed that the content of methyl eugenol and safrole in authentic asarum was much higher than that in non-authentic asarum. The content of methyl eugenol in three kinds of authentic asarum was: Seoul Asarum >: Asari Asarum > China Asarum, and the content of safrole was: China Asarum >: Asari Asarum > Seoul Asarum. There are also different medicinal parts. Traditional asarum is used as medicine from root, but now it is used from whole grass. The content of volatile oil is root, whole grass and leaf in turn. The harvest season is also different. Traditionally, it is harvested on the eighth day of the second day of the lunar calendar, when the active ingredients are the highest. But now driven by interests, there is no need to divide time, and its effective components are very unstable.

Therefore, the dosage of asarum depends on the specific situation. If it is right to follow the principle of "no money" at the end of use (whether it is used alone or in combination), then it must not be used in decoction, otherwise it will be useless, so it is no wonder that Chinese medicine is ineffective and useless.