The longer the mugwort is stored, the better! But it involves storage space, environment and other factors. If there are too many merchants, they will not store it for so long before realizing it. If you pick it yourself, it is best to store it before use after three years, but avoid moisture, mold, etc. As the saying goes, "If a family has three years of Ai, the doctor will not use it." Three years here is a prominent word - Chen! Because mugwort is a pure yang substance, new mugwort can be used for foot soaking and eating, but Chen mugwort must be used for moxibustion. Not only is new mugwort ineffective, it may also have toxic and side effects. Moxibustion works by burning pure Yang heat through the skin and acupoints into the meridians. It has special effects on deficiency and cold, and has a two-way regulating effect. The heat you feel here is not firepower! The concept is different.