What causes melatonin levels to change?
Melatonin is part of a sensitive, finely balanced physiological system that is programmed to be responsive to changes in the environment. Therefore melatonin rhythms can be changed by many factors, but exposure to light at night, many drugs and medicines, and changes to normal sleep habits can have dramatic effects on melatonin (which may persist beyond that night). It is therefore very important to appreciate and control for these factors when investigating possible influences on melatonin.
