What Is GHRP-6?

 GHRP-6 is short for growth hormone releasing peptide-6. It is a synthetic analogue of ghrelin that contains just six amino acids. It is also a potent growth hormone releasing factor. GHRP-6 is often referred to as a ghrelin receptor analogue because it binds to the ghrelin receptor. The amino acid sequence for GHRP-6 is Histidine-D-Trypotophan-Alanine-Tryptophan-D-Phenylalanine-Lysine.

It is worth nothing that D-Tryptophan and D-Phenylalanine are not amino acids that naturally occur in biological molecules. GHRP-6 is part of a series of compounds developed by Polygen (Germany) and Tulane University (United States) in an effort to created easily administered analogues of growth hormone releasing hormone1 .

Effects of GHRP-6

There are two primary effects of GHRP-6. The first is the release of growth hormone (GH) through interaction with the ghrelin receptor. Release of GH results in the release of insulin-like growth factor-1 (IGF-1) from the liver as well as the release of a multitude of other hormones and peptides. The net effect of GH release is the stimulation of growth in a number of organs including skeletal muscles and bone. Growth is the result of both hyperplasia (cell division and an increase in the number of cells in the tissue) as well as hypertrophy (increase in the size of cells). GH release also increases fat metabolism, decreases blood sugar (glucose) levels, increased cardiomyocyte (heart muscle cell) function, increased renal function2 , and improved memory.

The second effect of GHRP-6 is appetite stimulation. Ghrelin is a well-known appetite stimulant and the ghrelin receptor has long been a therapeutic target by scientists wishing to control appetite. Ghrelin is often referred to as the “hunger hormone.”

GHRP-6 has shown promise in rat models as an effective treatment against amyloid beta3 . Amyloid beta is one of the primary components of amyloid plaques, which appear in the brains of patients with Alzheimer’s disease. GHRP-6 has also been shown to affect levels of acetylcholinesterase (AChE), a molecule that plays an active role in cognition and memory.

A Note on GHRP-6 Biochemistry

GHRP-6 is not a growth hormone releasing hormone receptor (GHRHR) agonist. That is to say, GHRP-6 does NOT bind to the GHRHR, but rather produces all of its effects through the ghrelin receptor. Binding of the ghrelin receptor, by ghrelin or any other agonist, can and does lead to GH release4 . The importance of this distinction is that GHRP-6 has effects that differ from molecules like growth hormone releasing hormone and its analogues (GRF (1-29), CJC-1295, etc.). Learn more detailed information at

growth hormone releasing peptide


  1. Pralmorelin: GHRP 2, GPA 748, growth hormone-releasing peptide 2, KP-102 D, KP-102 LN, KP-102D, KP-102LN. Drugs RD5, 236-239 (2004).
  1. Rodriguez Salgueiro, S. et al. Role of epidermal growth factor and growth hormone-releasing peptide-6 in acceleration of renal tissue repair after kanamycin overdosing in rats. Iran. J. Kidney Dis.8, 382-388 (2014).
  1. Madhavadas, S., Kutty, B. M. & Subramanian, S. Amyloid beta lowering and cognition enhancing effects of ghrelin receptor analog [D-Lys (3)] GHRP-6 in rat model of obesity. Indian J. Biochem. Biophys.51, 257-262 (2014).
  1. Magdaleno-Méndez, A. et al. Ghrelin increases growth hormone production and functional expression of NaV1.1 and Na V1.2 channels in pituitary somatotropes. Endocrine48, 929-936 (2015).

What Is GHRP-2?

GHRP-2 is short for growth hormone releasing peptide-2. GHRP-2 is a synthetic peptide consisting of just seven amino acids (D-Ala-D-(β-naphthyl)-Ala-Ala-Trp-D-Phe-Lys). It is part of a series of compounds developed by Polygen (Germany) and Tulane University (United States) in an effort to create easily administered analogues of growth hormone releasing hormone1 . GHRP-2 is also known as GPA-748, pralmorelin, KP-102 D, DP-102 LN, DP-102D, and KP-102LN.

Effects of GHRP-2

GHRP-2 is a growth hormone (GH) secretagogue. It is NOT an agonist of the growth hormone releasing hormone receptor (GHRHR), but rather is an agonist of the ghrelin receptor. As a GH secretagogue, GHRP-2 causes the release of growth hormone, which in turn causes the release of insulin-like growth factor-1 (IGF-1) and a host of other hormones. The major effects of stimulating growth hormone release include hyperplasia (growth in cell numbers) and hypertrophy (growth in cell size) in bone and skeletal muscle. Additional effects include improve function of heart muscle (cardiomyocytes), increased lipid metabolism (fat loss), and decreases in blood sugar (glucose).

By stimulating ghrelin receptors, GHRP-2 also acts as an appetite stimulant. Research in lean, healthy human males, published in the Journal of Clinical Endocrinology and Metabolism, found a 35.9% increase in appetite among subjects receiving GHRP-2 injections compared to saline injections2 . Ghrelin is a known appetite stimulant and has been found to regulate growth hormone secretion as well.

Clinical Applications


GHRP-2 is currently under investigation in Japan as a treatment for short stature. It is under investigation in the United States as a potential treatment for GH deficiency. Tulane University currently holds a patent, issued in October 2002, for protection of its series of synthesized GH-releasing peptides. The patent includes GHRP-2. Get the latest news at

A 2004 study on rats found that GHRP-2 does not have any significant side effects on nervous system, smooth muscles, respiratory system, cardiovascular system, digestive system, or urinary system (kidneys). The hope is to eventually use GHRP-2 to both diagnose GH deficiency and treat short stature that results from GH deficiency3 .


  1. Pralmorelin: GHRP 2, GPA 748, growth hormone-releasing peptide 2, KP-102 D, KP-102 LN, KP-102D, KP-102LN. Drugs RD5, 236-239 (2004).
  1. Laferrère, B., Abraham, C., Russell, C. D. & Bowers, C. Y. Growth Hormone Releasing Peptide -2 (GHRP-2), like ghrelin, increases food intake in healthy men. J. Clin. Endocrinol. Metab.90, 611-614 (2005).
  1. Furuta, S. et al. General Pharmacology of KP-102 (GHRP-2), a Potent Growth Hormone-Releasing Peptide. Arzneimittelforschung54, 868-880 (2011).

Sermorelin. An Incredible Peptide

Over the last few years, there has been an increase in information on research peptides and peptide research on the net. Many people till date have never heard about research peptides, if you also don’t know, than type “research peptides” on Google search engine and you will find several in a minute!

What are peptides and Research peptides?

A peptide is a chain of amino acids that are linked to one another by peptide bonds. A peptide bond is the covalent chemical bond formed when the one amino acids’ carboxyl group reacts with the amino group of another. Research peptides are a chemical formula in the physical state which are available for research purpose.

There are several types and classes of peptides, on which the research focus that include ribosomal peptides, milk peptides, peptide fragments, and nonribosomal peptides.

There are several laboratories that synthesis peptides using MS (Mass Spectrometry) and HPLC (High-performance liquid chromatography). MS and HPLC help check the mass content and purity content of the sample. HPLC is usually performed many times during peptide synthesis while MS is used for result analysis.

By completing extensive research, scientists were able to synthesize various peptides, each more unique from the other. Research peptides such as Melanotan, Ipamorelin, a pentapeptide that display high gH releasing potency and efficacy in vivo and in vitro, Sermorelin, which were studied in clinical trials to test whether or not they could be used on humans.

Here I will focus on Sermorelin, 29 amino acid peptide of human growth hormone-releasing hormone (GHRH), which has been discovered as an effective way to fight the side effects of cellular degradation. It does this by triggering the brain to release an increased amount of growth hormone. Sermorelin Acetate GHRH has been approved for increasing growth hormone levels.


Research peptides have been discovered and supplied by several biotechnology firms in different physical forms such as powder, liquid, etc. Sermorelin is a GHRH analogue, which has molecular formula C149H246N44O42S and a molecular mass of 3357.96. It has been recognized as the shortest fully functional fragment of gH releasing hormone. Read related information at

What are the meaning of peptide purity and the role played by it in research?

Peptide purity usually ranges from over 70% to 99 %. This purity level is selected by the firm that requests custom peptide synthesis and purity varies based on the required use of the peptides. Peptides with a purity more than 70% are always used to test antibodies, while peptides with purity level over 85% are normally utilized for biological activity and enzymology studies. Peptides with purity over 95% are best for the quantitative analysis. Peptides with purity level more than 98% are excellent for non-commercial research.