Val,
5HTP, 5-hydroxytryptophan, is a precursor to serotonin. Trytophan is an amino acid(protein building block)that is metabolized to 5HTP and then to serotonin in the brain. Trytophan is no longer available in the United States and I believe that 5HTP is only used in research studies at this time. The SSRI's act to enhance the brains availabilty to utilize serotonin. Celexa, Paxil, Zoloft, Luvox and Prozac are considered SSRI's because they have some selectivity on there effect of serotonin. Serzone also acts on serotonin in even a more specific fashion than the SSRI's. In general all medications have side effects but the SSRI's are generally very well tolerated. I hope this was helpful.
Sincerely,
HFHS MD-JM