Key Findings
- GHRH promotes slow‑wave (deep) sleep and growth‑hormone release, while suppressing cortisol.
- CRH has the reverse effect, reducing deep sleep and increasing cortisol.
- Galanin, GHRP, and neuropeptide Y are sleep‑promoting, whereas ACTH(4‑9) disrupts sleep.
- Acute somatostatin worsens sleep in the elderly, but chronic vasopressin treatment improves it.
- Vasoactive intestinal polypeptide slows the NREM‑REM cycle and brings forward the cortisol low point.
Practical Outcomes
- For biohackers seeking better sleep, supplementing with GHRP (or other GHRH‑like agents) may enhance deep sleep, especially if combined with strategies that lower CRH activity (e.g., stress reduction). Avoiding compounds that raise CRH or ACTH(4‑9) levels could prevent sleep disruption. Chronic low‑dose vasopressin might be explored for older adults, but more safety data are needed.
Summary
Human studies show that several brain‑derived peptides directly change sleep patterns. Growth‑hormone‑releasing hormone (GHRH) boosts deep sleep and growth hormone while cutting cortisol, whereas corticotropin‑releasing hormone (CRH) does the opposite. Other peptides like galanin, growth‑hormone‑releasing peptide (GHRP), and neuropeptide Y also help sleep, while ACTH(4‑9) and short‑term somatostatin hurt it. Aging and depression shift the balance toward CRH, which may explain poorer sleep in those states.
Abstract
Results from preclinical studies have validated the participation of neuropeptides in sleep regulation. In recent human and clinical studies it has been shown that peripheral administration of various peptides results in specific changes in the sleep electroencephalogram in humans. Furthermore, it has been demonstrated that certain peptides are common regulators of the electrophysiological and neuroendocrine components of sleep. It is now well established that the balance between the neuropeptides growth hormone-releasing hormone (GHRH) and corticotropin-releasing hormone (CRH) plays a key role in normal and pathological sleep regulation. In young normal subjects, GHRH stimulates slow-wave sleep and growth hormone secretion but inhibits cortisol release, whereas CRH has the opposite effect. During normal aging and during acute depression, the GHRH:CRH ratio is changed in favor of CRH, resulting in disturbances in sleep endocrine activity. In addition to GHRH, galanin, growth hormone-releasing peptide, and neuropeptide Y also promote sleep, unlike ACTH(4-9), which disturbs sleep. In elderly subjects, sleep deteriorates after acute administration of somatostatin but improves after chronic treatment with vasopressin. Vasoactive intestinal polypeptide decelerates the non-rapid eye movement-rapid eye movement cycle and advances the occurrence of the cortisol nadir. The impact of delta sleep-inducing peptide, cholecystokinin, and thyrotropin-releasing hormone on human sleep regulation is not yet clear. This paper reviews recent work investigating the influence of these various neuropeptides on sleep.
Study Information
pubmed
1997