Xywav, with the 2-dose schedule. My impression based on how I feel waking up at various times in the morning is each dose produces effects that last somewhere around 3–5 hours. My understanding is most people taking this drug are falling asleep much more quickly than I am, and I do feel it trying to make me sleepy shortly after taking it, but not enough to defeat my delayed sleep phase disorder and various insomnia issues. But my point was that "falling asleep quickly" is not a direct goal of the drug, even if it is a common effect, the goal of the drug is to change what your brain does while you're asleep.