How to measure cortisol levels?

To measure cortisol levels effectively, there are a few key methods and considerations:

1. Blood Tests:

   • Cortisol levels can be measured through blood tests. It's important to take several samples at different times of the day because cortisol levels fluctuate throughout the day.
   • Dr. Andy Galpin notes that measuring cortisol at least three times a day (e.g., early morning, midday, and evening) is recommended to understand the daily pattern rather than relying on a single measurement 1.
   • Normal cortisol values can range widely (5-25 micrograms per deciliter), and these ranges vary by factors such as age, sex, and the specific method used for analysis 1.

2. Saliva Tests:

   • Saliva testing is another method to measure cortisol. It is particularly responsive to stress and activities immediately prior to the test.
   • According to Andrew Huberman, saliva testing measures free cortisol, the active form, giving direct insights into recent changes in cortisol levels 2.
   • This method is advantageous for its convenience and ability to measure rapid changes, though it may be less stable compared to blood testing.

3. Circadian Rhythm Consideration:

   • Andrew Huberman emphasizes that a healthy cortisol pattern typically has the highest levels in the morning, which helps wake you up. This level can spike around 50% with exposure to bright light early in the day, enhancing mood and alertness 2.
   • Monitoring cortisol levels throughout the day can provide insights into sleep issues or stress responses. If cortisol is highest in the afternoon instead of the morning, it may indicate underlying problems such as certain forms of depression 2.

These methods and approaches provide a comprehensive understanding of cortisol patterns and their implications for overall health.