Seriphos, and also ordinary phosphatidylserine, can in some people cause elevated norepinephrine, which makes a person jittery and unable to sleep. It's a genetic thing where some people's liver processes handle it differently.
A good forum to read about that is here, you can do a search there for the word "phosphatidylserine" to find posts of people who have the same problem with it: (some people on that forum handle this supplement just fine, but others have problems with it)