Typically cortisol is highest in the morning and drops during the day for most people. Some people have a “reverse” cortisol curve where it is higher at night instead of being highest in the morning. Obtaining a morning and late afternoon cortisol value provides more information regarding an individual’s daily fluctuation in cortisol. Also, in conjunction with DHEA-S the Cortisol test allows doctor the opportunity to better evaluate overall adrenal function. Since cortisol levels normally fluctuate throughout the day, a blood level is checked in the morning around 8 a.m. and again in the afternoon around 4 p.m. Fasting is not required for this test. Take all medications as prescribed.