What do your cortisol levels mean?
The short answer
Nobody on the record puts a target on cortisol. The quote below says why.
“There's no optimal exact level. There's no optimal level for one exact time.”
For cortisol, the range shifts with the time of day of the draw. Read yours against the range printed on your own report.
A typical lab range is 6.2–19.4 µg/dL.
What cortisol measures
Your main stress hormone. Your adrenal glands make it.
It follows a daily rhythm, high in the morning and low at night. So the time of the draw matters as much as the value.
Checked against MedlinePlus — Cortisol Test.
What changes your cortisol?
About the time of day.
“our cortisol levels begin to rise at nighttime and reaches its peak level in the morning”
About age and sex.
“so in a 24-hour cycle depending on your age and your gender there's a normal range for cortisol so it can go up and down like this”
About women in perimenopause, the years before menopause.
“as women are getting into par menopause which is in their 40s and we have more fluctuation of those hormones and an increase in Baseline cortisol anyway”
About stress.
“we know that stress does a number of things one it increases cortisol which is a stress hormone”
About sleep.
“take someone down down to five hours for just one night you immediately see this spike in the fight-or-flight nervous system blood pressure goes up you start to see cortisol increase heart rate starts to increase as well”
About women on the birth control pill.
“It seems to make the hypothalamic-pituitary-adrenal axis more rigid so that you can't kind of roll with the punches and wax and wane in terms of cortisol production the way that you can off the birth control pill”
Common questions
What is a normal cortisol level?
The normal range for cortisol depends on the time of day of the draw. Read your number against the range printed on your own report. The quotes on this page say what moves it. No physician or research scientist we follow has said how your cycle phase or hormone therapy changes cortisol.
What does your cortisol number mean?
Where it sits against the range your own report prints next to it. Nobody we follow has drawn a tighter line inside that range.
What does the cortisol test measure?
Your main stress hormone. Your adrenal glands make it. It follows a daily rhythm, high in the morning and low at night. So the time of the draw matters as much as the value.
Why is there no target here?
Because of this quote on video: “There's no optimal exact level. There's no optimal level for one exact time.” (Andrew Huberman, 1:14:37)