At the recommended doses, Tryptophan is considered completely safe.
Side effects only occur with high doses above the safe recommended dose. Tryptophan increases serotonin levels, and when to much is produced it can result result in tremors, nausea and dizziness. This condition is known as the “serotonin syndrome”, which can happen faster when using 5-HTP. Caused by an overabundance of serotonin, delirium, myoclonus, hyperthermia and coma can ensue. This happens rarely, but to be on the safe side never surpass the recommended dose.
Note: we are not medical professionals. Please seek proper medical advice for further information on the subject or when in doubt.