The reference values for Adrenocorticotropic Hormone (ACTH) tests can vary depending on the methods used by the laboratory. ACTH levels are measured in picograms per milliliter (pg/mL) of blood. Generally accepted reference ranges are as follows:

For blood samples taken in the morning: 10-50 pg/mL
For blood samples taken in the evening: 5-10 pg/mL

ACTH test results can be influenced by various physiological and psychological factors such as a person's sleep pattern, stress level, pregnancy status, menstrual period, or depression. Therefore, for an accurate interpretation of test results, it is critically important for a specialist physician to evaluate the person's overall health status, medication use, and existing symptoms as a whole. ACTH and cortisol levels are typically evaluated together due to their close relationship.