24hr Urine Cortisol

Collection Instructions

A 24-hour urine cortisol collection measures the total amount of cortisol excreted in the urine over a 24-hour period, providing insight into adrenal gland function and cortisol rhythm:

• Avoid stress, vigorous exercise, alcohol, and caffeine for at least 24 hours prior to and during the collection period, as these may affect cortisol levels.
• Do not collect urine during menstruation, as it may contaminate the sample.
• On the day of collection, begin after your first morning void—urinate and discard this first sample. Record the start time.
• From that point onward, collect all urine over the next 24 hours in the clean, dry, sterile container provided by your healthcare provider or laboratory.
• Store the container in a cool, dark place (preferably refrigerated) throughout the 24-hour period to preserve the sample.
• Include the first morning urine at the end of the 24-hour period. This is the final sample, and it marks the end of the collection period. Record the end time.
• Deliver the full container to your healthcare provider or laboratory as instructed.
• Be sure to record any medications or supplements taken during the collection period and note any missed urine samples, if applicable.