OVERVIEW

Ipamorelin is a highly selective growth hormone secretagogue (GHS) that binds specifically to the ghrelin/growth hormone secretagogue receptor (GHS-R1a). It is one of the most targeted GH secretagogues, meaning it does notaffect levels of ACTH, prolactin, follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), or cortisol.

Due to its high receptor specificity, Ipamorelin has been widely studied for therapeutic applications and as a model peptide for exploring GH receptor selectivity. It plays a key role in growth, tissue repair, and metabolic regulation.

RESEARCH

Ipamorelin and Growth Hormone Release

Ipamorelin mimics ghrelin, the body’s natural hunger hormone, by binding to GHS-R1a receptors. This interaction leads to:

• A natural increase in growth hormone (GH) levels.
• Improved muscle growth, fat metabolism, and tissue repair.
• Preserved GH pulse frequency without overstimulating the endocrine system.

Unlike other GH secretagogues, Ipamorelin stimulates GH release without causing significant increases in cortisol or prolactin levels, making it a safer option for long-term use.

Ipamorelin and Corticosteroid Side Effects

Glucocorticoids (steroids) are often used to treat inflammatory diseases and cancer, but long-term use can lead to:

• Muscle wasting
• Loss of bone density
• Increased visceral fat accumulation

Studies suggest that Ipamorelin may counteract these side effects by:

• Reducing muscle breakdown.
• Preventing bone loss associated with prolonged steroid use.
• Preserving nitrogen balance, which is crucial for muscle maintenance and recovery.

Ipamorelin and Bone Health

Chronic steroid use is linked to osteoporosis and increased fracture risk. Research in animal models has demonstrated that Ipamorelin can:

• Prevent bone density loss.
• Stimulate osteoblast activity, promoting new bone formation.

These findings suggest Ipamorelin may have therapeutic applications in conditions like osteoporosis and age-related bone deterioration.

Ipamorelin and Muscle Growth

Ipamorelin’s ability to enhance protein synthesis makes it beneficial for:

• Increasing muscle mass and improving recovery.
• Preventing muscle wasting conditions, such as cachexia and sarcopenia.
• Supporting post-surgical healing and injury rehabilitation.

By promoting muscle hypertrophy and repair, Ipamorelin has gained interest in sports medicine and anti-aging research.

Ipamorelin and Diabetes Research

Studies suggest that Ipamorelin can stimulate insulin release by activating calcium channels in pancreatic islet cells. This mechanism may:

• Improve insulin sensitivity.
• Aid in blood sugar regulation.

These findings indicate that Ipamorelin may be explored as a potential treatment for diabetes.

Ipamorelin and Post-Operative Ileus (POI)

Post-operative ileus (POI) occurs when the digestive tract temporarily stops functioning after surgery, delaying recovery.

Clinical trials have shown that Ipamorelin:

• Reduces POI symptoms.
• Shortens hospital stays by an average of 12 hours.

Although initial results were promising, further research on Ipamorelin for POI treatment was discontinued due to insufficient efficacy in large-scale trials.

Ipamorelin and PET Imaging

As a potent ghrelin receptor agonist, Ipamorelin has potential applications in diagnostic imaging:

• Could be used in PET scans to detect ghrelin receptor-overexpressing tumors.
• May aid in diagnosing conditions related to GH deficiency or metabolic disorders.

STRUCTURE

• Molecular Formula: C₃₈H₄₉N₉O₅
• Molecular Weight: 711.868 g/mol
• Amino Acid Sequence: Aib-His-D-2Nal-D-Phe-Lys
• CAS Registry Number: 170851-70-4
• PubChem Identifier: 9831659

CITATIONS

1. Raun, K. et al. Ipamorelin, the first selective growth hormone secretagogue. Eur. J. Endocrinol. (1998).
2. Andersen, N. B. et al. The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced bone loss. Growth Horm. IGF Res. (2001).
3. Svensson, J. et al. Ipamorelin increases bone mineral content in female rats. J. Endocrinol. (2000).
4. Aagaard, N. K. et al. GH secretagogues reduce nitrogen loss in steroid-treated rats. Growth Horm. IGF Res. (2009).
5. Adeghate, E. & Ponery, A. S. Ipamorelin stimulates insulin release in diabetic rats. Neuro Endocrinol. Lett. (2004).
6. Beck, D. E. et al. Ipamorelin for management of post-operative ileus in bowel resection patients. Int. J. Colorectal Dis. (2014).
7. Greenwood-Van Meerveld, B. et al. Ipamorelin improves gastric dysmotility in POI models. J. Exp. Pharmacol. (2012).
8. Fowkes, M. M. et al. Peptidomimetic GH secretagogue derivatives for PET imaging. Eur. J. Med. Chem. (2018).