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Shanghan Lun and Jingui Yaolue collectively contain 25 formulas involving Gypsum decoction, none of which mention the need to "be decocted first." Some formulas even avoid prolonged decoction, such as White Tiger Decoction, where Gypsum is decocted together with rice and other herbs until the rice is cooked, forming the decoction. By modern timing, "rice cooked" would take no more than 30 minutes. The remarkable heat-clearing effect of White Tiger Decoction has been praised by renowned physicians throughout history, and numerous clinical cases have confirmed that Gypsum does not need to "be decocted first" to exert its excellent heat-clearing properties.

Zhang Zhongjing also employed the method of "to be decocted first" in his formulas. Among the 113 formulas in Shanghan Lun, 36 require "decocting first." The ingredients that are decocted first are mostly the main herbs in the formula, such as Ephedra Decoction with Ephedra, Pueraria Decoction with Pueraria Root, Virgate Wormwood Decoction with Virgate Wormwood, Sour Jujube Decoction with Sour Jujube, Poria, Cinnamon Twig, Bighead Atractylodes and Licorice Decoction with Poria, and Minor Chest Bind Decoction with Trichosanthis Fruit, among others. Gypsum is the main herb in White Tiger-type decoctions, yet the texts never mention "decocting first." The author believes this is not an oversight or antagonism; Zhang Zhongjing was very particular about the decoction method for Gypsum. For example, both White Tiger Decoction and Bamboo Leaf and Gypsum Decoction use one jin of Gypsum. White Tiger Decoction treats high fever and has a short decoction time (one dou of water, boiled until the rice is cooked), while Bamboo Leaf and Gypsum Decoction treats low fever and has a longer decoction time (one dou of water, boiled down to six sheng, then rice is added and boiled until cooked). Other formulas containing Gypsum that do not target intense heat, such as Major Blue Dragon Decoction, Ephedra, Bitter Apricot Seed, Gypsum and Licorice Decoction, Spleen-Qi Effusing Decoction, and Gui Er Yue Yi Tang, all use prolonged decoction, suggesting that extended boiling may reduce Gypsum's heat-clearing potency. If so, those wishing to use Gypsum to clear intense heat should not "decoct first" (prolonged boiling).

The renowned late Qing physician Zhang Xi-chun was a modern representative of the effective use of Gypsum. In his formulas, Gypsum is either decocted with other herbs or finely ground and taken as an infusion, with no mention of "decocting first." The modern Chinese medicine master Pu Fu-zhou frequently used Gypsum-containing decoctions to reduce high fever. A thorough review of his medical cases reveals no instances of Gypsum being "decocted first." ...

In the 1950s, Mr. Shi Yiren proposed that "Gypsum is heavy in quality... only after prolonged boiling in water can a portion of its active ingredients be dissolved." Since then, those who advocate for Gypsum to be decocted first have followed this theory. However, what the effective heat-clearing component of Gypsum is remains undetermined to this day. Some scholars believe that the active ingredient in Gypsum is its hydrated calcium sulfate... From the perspective of transformation in accord with constitution, Gypsum is a slightly soluble substance with very low solubility. Its solubility at 100°C is even less than at 40°C, and even at its maximum solubility at 40°C, only 0.21g can be dissolved in every 100g of water. The temperature during decoction is generally above 100°C, which is when Gypsum has the least solubility. Moreover, prolonged boiling reduces the solvent (water), causing some of the dissolved Gypsum to recrystallize. The longer the boiling time, the lower the Gypsum content in the decoction. If calcium sulfate is the active ingredient in Gypsum, wouldn't decocting Gypsum first reduce the content of active ingredients in the decoction?

Someone used atomic absorption spectrometry to determine Ca, Fe, Mn, Zn, and Cu in Gypsum, Ephedra, Bitter Apricot Seed, Gypsum and Licorice Decoction decocted alone, and mixed decoctions, and conducted a comparative analysis. It was found that when Gypsum was decocted together with Bitter Apricot Seed, Ephedra, and Liquorice Root, the measured values of the mixed decoctions were mostly higher than the sum of the values obtained from the two herbs decocted alone, especially for Ca, Fe, and Zn. The increase in elemental content was most significant in the mixture of Gypsum and Ephedra, possibly due to the strong complexation between metal ions and Ephedra alkaloid molecules. This suggests that the pharmacological effects of compound formulas containing Gypsum decoction may be attributed to the action of metal complexes.

Additionally, it has been reported that the mixed decoction of raw Gypsum and Rhubarb Rhizoma has a significantly stronger antipyretic effect on feverish rabbits compared to the decoction of Gypsum alone. This indicates that decocting Gypsum with other herbs can enhance its efficacy, and there is no need to decoct it separately first.

Decocting Gypsum first is time-consuming and fuel-intensive, which is neither a traditional Chinese medicine practice nor supported by reasonable scientific explanations. Over a thousand years of clinical practice have confirmed that decoctions containing Gypsum achieve good efficacy without the need for decocting it first. Moreover, since the active components and mechanisms of Gypsum are still unclear, there is currently no need to emphasize "decocting it first."