GHRP-6
One of the first GHRPs developed, known for stimulating significant appetite and GH release.
Common Dosage
100mcg - 300mcg 2-3x daily
Category
Growth Hormone
- Extreme appetite stimulation
- GH release
- Gastric motility
GHRP-6 was one of the earliest growth hormone releasing peptides synthesized and studied, emerging from research in the 1980s as part of efforts to understand the regulation of GH secretion. It was instrumental in the discovery of the ghrelin receptor system. Historically, GHRP-6 was used in clinical research to test pituitary GH reserve and assess GH deficiency. Its characteristic extreme appetite stimulation — more intense than any other GHRP — initially made it problematic for anti-aging use but has been explored for appetite stimulation in cachexia and anorexia research.
GHRP-6 is a synthetic hexapeptide that acts as a potent agonist at GHS-R1a receptors. It stimulates robust GH pulses through direct pituitary action and hypothalamic somatostatin suppression, similar to GHRP-2. However, its higher ghrelin receptor affinity and different binding kinetics produce more intense hunger, and it generates greater cortisol and prolactin elevation than newer GHRPs. Its appetite effect is mechanistically linked to its ghrelin mimicry — ghrelin is a hunger hormone.
- GH deficiency testing and stimulation protocols
- Cachexia and wasting-associated appetite stimulation
- Gastric motility and GI protection research
- Muscle growth in combination with CJC-1295
- Anti-inflammatory properties research
Appetite Stimulation in Wasting
In research settings, GHRP-6 has demonstrated reliable appetite stimulation in patients with cancer cachexia and other wasting syndromes — an application where its primary 'side effect' becomes its main therapeutic asset. The combined GH-releasing and appetite-stimulating mechanism creates a dual anabolic environment.
Cytoprotective Effects
Independent of its GH-releasing effect, GHRP-6 has demonstrated direct cytoprotective effects on cardiac and liver tissue in ischemia models — suggesting anti-apoptotic mechanisms beyond the GH axis.
- Extreme and difficult-to-ignore hunger — makes controlled eating almost impossible during dosing periods
- Significant cortisol and prolactin elevation with frequent dosing
- Prolactin elevation is a particular concern for men — associated with libido reduction and potential gynecomastia
- Water retention from GH elevation
- Not appropriate for individuals in caloric restriction or those managing eating disorders
- Superseded by cleaner alternatives (Ipamorelin) for most anti-aging applications
- Extreme hunger
- Water retention
- Prolactin elevation