Andrew Huberman· PhD
when I take tryptophan, or anything that contains 5-HTP, which is serotonin or a precursor to serotonin, serotonin is made from tryptophan, I tend to fall very deeply asleep and then wake up a few hours later. And that makes sense now based on the fact that, you just don't want a lot of REM sleep early on. What was probably happening is that I was getting a lot of REM sleep early on, because low levels of serotonin are typically associated with slow wave sleep and that comes early in the night.