Does coffee make your stress hormone stop reacting?
Caffeine Stimulation of Cortisol Secretion Across the Waking Hours in Relation to Caffeine Intake Levels
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Cortisol remained elevated for up to 6 hours after an afternoon caffeine dose—even in heavy users (600 mg/day).
Most assume tolerance means the body stops responding entirely, but this shows the stress system stays activated long after caffeine is consumed, potentially disrupting sleep and anxiety levels.
Practical Takeaways
Avoid caffeine after 1 PM if you struggle with anxiety or sleep—your cortisol will still spike, even if you're a daily coffee drinker.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Cortisol remained elevated for up to 6 hours after an afternoon caffeine dose—even in heavy users (600 mg/day).
Most assume tolerance means the body stops responding entirely, but this shows the stress system stays activated long after caffeine is consumed, potentially disrupting sleep and anxiety levels.
Practical Takeaways
Avoid caffeine after 1 PM if you struggle with anxiety or sleep—your cortisol will still spike, even if you're a daily coffee drinker.
Publication
Journal
Psychosomatic Medicine
Year
2005
Authors
W. Lovallo, T. Whitsett, M. al’Absi, B. Sung, Andrea S. Vincent, Michael F. Wilson
Related Content
Claims (6)
Taking 600 mg of caffeine per day for five days leads to a smaller increase in cortisol levels after a later caffeine dose compared to taking 300 mg per day, suggesting the body's stress hormone system adjusts more strongly at higher doses.
Even after taking 600 mg of caffeine daily for five days, the body still shows a measurable increase in cortisol levels after a subsequent dose, indicating that the stress response to caffeine does not fully disappear with short-term daily use.
Taking 300 or 600 milligrams of caffeine daily for five days lowers the cortisol spike that occurs when you later take another 250 milligrams of caffeine, but cortisol levels still rise significantly, especially after afternoon doses, showing that the body does not fully adjust to caffeine over this period.
Even when people drink 300 mg of caffeine daily, their cortisol levels stay higher than normal for up to six hours after an afternoon dose, showing that the body's stress response system does not fully adjust to this level of caffeine intake.
After five days without caffeine, the body's cortisol response to a 250 mg dose of caffeine returns to its original strength, suggesting that tolerance to caffeine is temporary and linked to recent use, not permanent changes in the body.