I would say be careful with 5HTP. I took it once for relaxation at night and it kept me up all night - very bad night for me - same thing happened to a friend of mine. I take tryptophan and it works very well. It is relaxing and helps me sleep.
I would try 5HTP on a day when I didn't have to work and during the day to see what the effect has. I think it may be different for different people.