L-theanine can have a mild anti-anxiety effect and may improve sleep, but can also make dreams more vivid, potentially disrupting sleep for some individuals.

“and then the third is theanine which is known to have a a mild uh anti-anxiety uh component to it — the one caveat is that theanine can be problematic for people that have very vivid dreams it can often people say that it makes their dreams even more Vivid and so if you suffer from that or it's waking you up then I suggest leaving out the theanine”