The zona fasciculata (sometimes, fascicular or fasciculate zone) constitutes the middle and also the widest zone of the adrenal cortex, sitting directly beneath the zona glomerulosa.

The zona fasciculata chiefly produces glucocorticoids (mainly cortisol in humans), which regulate the metabolism of glucose.

Glucocorticoid production is stimulated by adrenocorticotropic hormone (ACTH)[1], which is released from the anterior pituitary, especially in times of stress as part of the fight-or-flight response.

The zona fasciculata also generates a small amount of weak androgens (e.g., dehydroepiandrosterone).

In certain animals such as rodents, the lack of 17alpha-hydroxylase results in the synthesis of corticosterone instead of cortisol.