Liao Swun-fu of the Huang Chang-sheng Herbal Pharmacy explains that only they were believed to have absorbed enough life energy. It was a concept that served to protect life. "But now that the amount being used is so great, how can you find enough shells of turtles that died of natural causes?" Many herbal medicine dealers say that shells of Reeve's turtle from Mainland China are best.
歷代中藥書上也記載，最具療效的龜板是「敗龜板」，意指自然死亡的烏龜，黃長生中藥行老闆廖孫福表示，相傳敗龜板才能吸收足夠的大自然真氣，但其實兼有護生的意義，只是「今天使用數量太多，哪裡還有敗龜板可用？」