I experienced severe anxiety after taking l-tryptophan. what do you think the reason was?

Don't take: L- Tryptophan is an amino acid commonly found in turkey meat and other foods in low amounts. Your body converts L-Tryptophan into serotonin which controls mood and sleep. Unfortunately commercial preparations of L-Tryptophan have a high level of undesirable side effects, including mood swings, lethargy, etc. They can also react with meds called SSRI's producing extreme anxiety.

Many possibilities: Other causes can be, interaction with other supplements or medications other than SSRI's. While most people feel calmer, others can have the opposite reaction. That is true for many things. Also, the natural supplement industry is not regulated very well in this country, most are poor quality; there are only a few companies that have true pharmaceutical compliance, especially on the internet.