Concordant and discordant adrenocorticotropin (ACTH) responses induced by growth hormone-releasing peptide-2 (GHRP-2), corticotropin-releasing hormone (CRH) and insulin-induced hypoglycemia in patients with hypothalamopituitary disorders: evidence for direct ACTH releasing activity of GHRP-2.
Kimura. Takashi T; Shimatsu. Akira A; Arimura. Hiroshi H; Mori. Hideki H; Tokitou. Akinori A; Fukudome. Michiyo M; Nakazaki. Mitsuhiro M; Tei. Chuwa C
Key Findings
- GHRP-2 caused a clear rise in ACTH levels in all six patients tested.
- The rise occurred even though the insulin‑induced hypoglycemia test (ITT) failed to stimulate ACTH or cortisol.
- CRH also raised ACTH, confirming that the pituitary could still respond, and GHRP-2’s effect appears to be a direct action on ACTH release.
Practical Outcomes
- For biohackers using GHRP-2, be aware it can increase ACTH and therefore cortisol, which may affect stress, sleep, and metabolism. This isn’t a new dosing protocol, but it suggests monitoring cortisol‑related side effects when stacking GHRP-2 with other hormones.
Summary
The study found that the peptide GHRP-2, which is known for boosting growth hormone, also directly triggers the release of ACTH (a hormone that tells the body to make cortisol) in people with pituitary problems, even when other stress tests don’t work.
Abstract
The insulin-induced hypoglycemia test (insulin tolerance test: ITT) and corticotropin-releasing hormone (CRH) test are used to examine the activities of the hypothalamo-pituitary-adrenal (HPA) axis. Growth hormone-releasing peptide-2 (GHRP-2), a potent GH secretagogue, also stimulates adrenocorticotropin (ACTH) secretion. To evaluate the role of GHRP-2 in assessing the HPA axis, we examined 6 patients with various hypothalamo-pituitary disorders, and measured ACTH and cortisol responses during provocative tests (ITT, CRH, and GHRP-2 test). None of the 6 patients showed any significant ACTH or cortisol responses to ITT, but significant ACTH release was observed during CRH and GHRP-2 tests. These findings suggest GHRP-2 may directly stimulate ACTH secretion in patients with hypothalamo-pituitary disorders.
Study Information
pubmed
2010
2010-04-17T00:00:00.000Z
10.1507/endocrj.k10e-017