Does Coffee Raise Cortisol?

How does coffee raise cortisol?

Caffeine stimulates the adrenal glands to release cortisol and adrenaline by blocking adenosine receptors and activating the hypothalamic-pituitary-adrenal (HPA) axis. This is the same hormonal pathway activated by stress. A 2005 study in Psychosomatic Medicine found that caffeine significantly elevated cortisol levels in both rested and sleep-deprived participants, with the effect being more pronounced in people who were already stressed.

The cortisol spike typically peaks 30 to 60 minutes after consumption and can persist for several hours, depending on individual caffeine metabolism.

Why does the timing of your coffee matter for cortisol?

Cortisol follows a natural daily rhythm called the cortisol awakening response (CAR). Levels peak naturally 30 to 45 minutes after waking, then decline through the morning. Drinking coffee during this natural peak (roughly 8 to 9am for most people) adds a caffeine-driven cortisol spike on top of an already-elevated baseline.

Drinking coffee after the natural peak has subsided (roughly 9:30 to 11:30am) produces a smaller net cortisol increase. This is why many people report feeling less anxious from the same amount of coffee when they delay their first cup by an hour after waking.

Does matcha raise cortisol like coffee?

Matcha raises cortisol less than coffee for two reasons. First, it contains roughly half the caffeine of a standard cup of coffee (approximately 70mg per 2g serving vs 95 to 200mg in drip coffee). Second, matcha contains L-theanine, an amino acid that modulates the HPA axis response to caffeine. A 2019 study in Nutrients found that L-theanine significantly reduced physiological stress responses, including cortisol, compared to caffeine alone.