L-Tryptophan has a 12 hour half-life so it should be taken twice a day. Split the daily dose and take it am and pm.

Do not take 5-HTP with L-Tryptophan. L-Tryptophan is a precursor of 5-HTP. L-Tryptophan enters the system before the body's metering system. This means the body processes it into 5-HTP as it needs it. 5-HTP enters after this metering system and can cause an over-dose or roller coaster of the level of 5-HTP. This can cause sweating, nervousness, twitching, and some more severe symptoms of serotonin syndrome.