As long as you do not exceed 50mg of 5-HTP 2 times a day(upon awakening and before going to bed), you should be fine.
Now you probably think "But if i take it upon awakening, I will fall asleep!". Wrong. THe melatonin conversion only happens at nighttime. During the day, 5-HTP converts to serotonin, the happy hormone
Try googling for 5-HTP. There is a ton of information on the web.