It really varies from person to person, and what you are trying to accomplish. Were you diagnosed with depression, and your doctor perscribed an ssri, or are you just looking for a mood boost? Also, if you naturally have a low libido, you might want to get a full hormone panel done, including having your sero/dopamine levels checked to see what might be going on before screwing with 5htp, which just might make matters worse, especially if you take too much. Also, talk to your doctor about bupropion, aka Wellbutin/Zyban, it has positive effects on libido. Otherwise, like Andrew said, Bocopa, l-theanine, and macuna prureins, would be a good start.