GHRP-6
Growth Hormone Releasing Peptide-6, Growth hormone-releasing hexapeptide, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2
Growth hormone (GH)-independent stimulation of adiposity by GH secretagogues.
Lall. S S; Tung. L Y LY; Ohlsson. C C; Jansson. J O JO; Dickson. S L SL
Key Findings
- GHS peptides (ipamorelin, GHRP‑6) increase body fat in both GH‑deficient and normal mice without needing extra GH.
- These peptides raise serum leptin and stimulate food intake in GH‑intact mice.
- Direct GH administration reduces fat in GH‑deficient mice but has little effect on normal mice, highlighting a distinct mechanism for GHS‑induced fat gain.
Practical Outcomes
- If you’re using GHRP‑6 or similar peptides to boost performance or recovery, expect a possible rise in appetite and body fat, which may counteract cutting or leanness goals. Consider limiting dose, timing, or pairing with strict diet control if you want to avoid unwanted weight gain. Conversely, the appetite‑stimulating effect could be useful for those needing to increase caloric intake.
Summary
In mice, the growth‑hormone‑releasing peptides ipamorelin and GHRP‑6 make animals gain body fat even when they don’t boost growth hormone levels. The extra fat comes with higher leptin and more eating, showing the peptides can drive weight gain through a GH‑independent route.
Abstract
Growth hormone secretagogues (GHSs) stimulate growth hormone (GH) secretion, which is lipolytic. Here we compared the effects of twice daily s.c. treatment of GH and the GHS, ipamorelin, on body fat in GH-deficient (lit/lit) and in GH-intact (+/lit and +/+) mice. In +/lit and lit/lit mice ipamorelin induced a small (15%) increase in body weight by 2 weeks, that was not further augmented by 9 weeks. GH treatment markedly enhanced body weight in both groups. Ipamorelin also increased fat pad weights relative to body weight in both lit/lit and +/lit mice. Two weeks GHS treatment (ipamorelin or GHRP-6) also increased relative body fat, quantified by in vivo dual energy X-ray absorpiometry (DEXA) in GH-intact mice. GH decreased relative fat mass in lit/lit mice and had no effect in GH-intact mice. Treatment with GHS, but not GH, increased serum leptin and food intake in GH-intact mice. Thus, GHSs increase body fat by GH-independent mechanisms that may include increased feeding.
Study Information
pubmed
2001
2001-01-12T00:00:00.000Z
10.1006/bbrc.2000.4065