Sun Yaozhong was already about 47,000 years old this year. Under normal circumstances, the lifespan of a Dacheng Quasi-Immortal could reach up to 50,000 years, but 50,000 years was only the theoretical maximum lifespan.
Basically, all Dacheng Quasi-Immortals could not live to 50,000 years old. At most, they would die at about 49,000 years old, or even less. Many of them would only live to about 48,000 years old.
For his only son, Sun Yaozhong had suffered a great loss of vitality many times over the years. It was already good enough for him to live to 48,000 years old, so he only had a few hundred years left to live.
Using such a precious secret medicine in exchange for several hundred years of Sun Yaozhong's time, let alone others, even Sun Yaozhong himself felt that it was worth it.
Having lived in the cultivation world for so many years, Sun Yaozhong clearly knew what kind of price many cultivators above the dacheng stage paid in order to have children.