Use 20g of Radix Rehmanniae each time, 1 to 2 duck eggs, add appropriate amount of water and stew with water. After the eggs are cooked, shell them, then stew them in juice for 20 minutes and season them with rock sugar. Eat eggs and drink juice/kloc-0 once a day or 2 ~ 3 times a week. It has the effects of nourishing yin, clearing away heat, promoting fluid production and quenching thirst, and is suitable for people with dry mouth and throat and swollen gums after staying up late.