Tryptophan is an essential amino acid that helps your body produce melatonin and serotonin. However, it's not why you feel tired after a large meal.

We could all use a little extra serotonin in our lives. Luckily, one of the easiest ways to give yourself a natural boost is ...

When a molecule of tryptophan absorbs ultraviolet light, it glows faintly as it releases energy at a lower frequency. This effect, called fluorescence, is well known. But something extraordinary ...