This is interesting - I was going to try 5HTP for my SAD this winter, at the moment I take St John's Wort and use a light box.
Anyone used St John's wort before and can compare how effective the StJ's is compared with the 5HTP?
BTW an article I read in a magazine (Human Givens, Volume 9, no4) suggested you shouldn't take StJ's and 5HTP together since St J's works by blocking serotonin breakdown and 5HTP leads to you making more serotonin, so the two together could result in too high levels of serotonin which is quite nasty apparently.