Stress, endocrine & the HPA axis

DSIP’s clearest human signal is not about sleep at all

Ironically, DSIP’s best-replicated human signal is endocrine, not hypnotic. Two of the three fetched human studies report a fall in the stress hormone precursor ACTH after intravenous DSIP and a third reports none, while cortisol and vasopressin responses stay intact. That is a disputed but real touch on the HPA axis, and it is not the same thing as lowering cortisol.

This unit follows that stress-axis story, the LH and somatostatin findings, and the Cushing-syndrome data that complicates any tidy "DSIP equals more deep sleep" narrative.