According to Dr. Robert Atkins, he states in one of his books ('Vita-Nutrient Solution' I think) that 5-HTP should be taken at night ...that it is a wonderful supplement for insomnia (if I remember correctly, it aids in your quality of sleep). In fact, he also strongly recommends that before bed is also a great time to take calcium supplements ...it is known to aid with sleep as well (as a sleep inducer?). I have found this out to be true for myself.