I discovered quite accidentally that a strong cup of ginger tea brewed from fresh ginger slices taken one hour before bedtime makes me sleep. After years of using medications, both prescription and over-the-counter, to induce sleep I found that ginger tea, for me, has a soporific effect. Since I couldn't find anything on the web explaining this phenomenon, I looked up information on some Chinese language websites. Only one explained the use of ginger as a sleep agent. Apparently, it works only for people who are "pa leng" or "afraid of cold." This means, if you have the tendency to have cold fingers and toes you may benefit from ginger tea as a sleep agent. Anyway, it works for me.