Understanding Growth Hormone Peptides

What are hormones?

Hormones are chemical substances within the body that act as messenger molecules. They send signals from your blood’s circulation into your organs, tissues, and muscles. Hormones can initiate the onset or cessation of several bodily functions, and therefore, are a critical component to your health and wellbeing.

Experts have identified greater than 50 hormones in humans. Each serves different functions in the body, including but not limited to:

• Growth and development
• Metabolism
• Homeostasis
• Sexual function
• Reproduction
• Mood
• Sleep¹

Growth hormones in particular are critical to your development and health. This article will discuss the ins and outs of specific growth hormones, including their mechanisms, benefits, and safety profile.

What do growth hormones do?

Human growth hormone, often referred to as somatotropin and hGH, works to promote growth throughout the body. It also serves other functions, such as maintaining your metabolism, body structure, and blood sugar levels.

Your body naturally produces hGH via the pituitary gland. The pituitary gland is a small part of your endocrine system that serves a critical purpose. The pituitary gland interfaces with hypothalamus, a regulator of temperature, blood pressure, digestion, and heart rate. The hypothalamus produces growth hormone-releasing hormone (GHRH), which in turn activates the pituitary gland to release hGH².

What are growth hormone peptides?

As aforementioned, hGH is naturally produced by the body. However, healthcare providers will sometimes utilize a synthetic form of growth hormone that is man-made². Growth hormone peptides work similarly to your natural hormones, stimulating the release of growth hormones from the hypothalamus and pituitary gland³.

What is growth hormone peptide therapy?

Growth hormone peptide therapy involves the administration of prescription growth hormones such as ipamorelin, sermorelin, or CJC1295. It is designed to replenish hormones that your body naturally produces but may not release in sufficient quantities. The remainder of this article will discuss major growth hormone peptides, including sermorelin, ipamorelin, CJC-1295, BPC-157, and PT-141.

Sermorelin

Mechanism

Sermorelin is a growth hormone peptide that healthcare providers sometimes prescribe for longevity-related conditions. Sermorelin is an analog of natural GHRH, meaning that it is chemically and structurally similar to GHRH. It binds to certain receptors on the pituitary gland, promoting the production and release of your body’s natural hGH⁴.

Benefits

Research indicates that sermorelin administration elevates hGH concentrations in the blood. For this reason, physicians sometimes use sermorelin to treat poor growth and development in children. One study found that daily injections of sermorelin increased growth parameters in children deficient in growth hormone⁵.

Outside of its benefits in younger individuals, sermorelin has also demonstrated efficacy in adults. An older study found that daily sermorelin administration increased factors related to quality of life in adult men and women. Such factors included improved sleep quality in men and women. Men also had statistically significant improvements in libido and overall wellbeing. Additionally, sermorelin caused a significant increase in lean body mass and skin thickness⁶.

Safety

Sermorelin may cause certain side effects, including injection site reactions. These include symptoms of itching, redness, irritation, swelling, or pain at the injection site. However, these reactions are usually transient and self-limiting. Other side effects include flushing, restlessness, trouble swallowing, headache, dizziness, or nausea. Sermorelin can also interact with other drugs and medications⁷.

Ipamorelin

Mechanism

Ipamorelin is another growth hormone peptide that mimics a bodily substance known as ghrelin. Ghrelin plays a role in regulating hunger, food intake, and fat storage. It is also implicated in maintaining energy and blood sugar levels.

By mimicking ghrelin, ipamorelin binds the ghrelin receptor, also known as the GH secretagogue receptor (GHSR), in the brain. GHSR receptor binding activates GH release from the pituitary gland, increasing GH concentration in the blood and influencing several bodily processes⁸.

Benefits

In human clinical studies, ipamorelin administration increased GH levels after injection. Because of its effects on growth hormone, ipamorelin is hypothesized to have several clinical advantages related to increase GH concentrations⁹. For example, studies have shown that it has potential to increase gastric motility, thus helping with conditions such as postoperative ileus (POI)¹⁰.

Safety

In animal models, male rats receiving ipamorelin experienced increased food intake and body weight gain¹⁰.

Ipamorelin/CJC-1295

Mechanism

GHRH has a short half-life, meaning that it does not last long in the body. CJC-1295 is a synthetic form of GHRH aimed at solving this problem, as it has a longer half-life¹¹. Research has postulated that CJC-1295 and ipamorelin can be used together for optimized efficacy.

Safety

One study evaluating CJC-1295 administration noted that side effects of CJC-1295 were mild to moderate in severity. The primary side effects were injection site reactions, which include symptoms such as redness, itching, irritation, or pain. However, these effects were short-lived and resolved within several hours. Some subjects experienced headache, diarrhea, low blood pressure, and flushing¹¹.

BPC-157

Mechanism

BPC-157 is a peptide that has potential cytoprotective, anti-inflammatory, and protective organ effects.

Efficacy

BPC-157 is a peptide that has demonstrated protective effects within the various tissues, including the muscles, bone, skin, and tendons in animal models. Additionally, it has demonstrated positive effects gastrointestinal tract. BPC-157 also has potential applications in nervous system disorders. For example, in rat models, BPC-157 helped resolve issues with memory, movement, and coordination as a result of stroke. It also increased healing and recovery in rats experiencing spinal cord compression. Therefore, BPC-157 has potential benefits in treating conditions related to the GI tract, cardiovascular system, and nervous system^12,13.

Safety

In animal models in rats, mice, rabbits, and dogs, BPC-157 was well-tolerated and did not result in any serious adverse effects. BPC-157 administration was associated with mild irritation¹⁴. Likewise, BPC-157 is likely safe in humans, however, few human clinical studies exist¹⁵.

PT-141

Mechanism

PT-141 is a manmade peptide that resembles alpha-Melanocyte-stimulating hormone (alpha-MSH), a natural hormone implicated in maintenance of the hair and skin. PT-141 acts on the MC3R and MC4R receptors in the central nervous system¹⁶.

Efficacy

PT-141 administration has demonstrated positive effects in men with erectile dysfunction. With increased doses of PT-141, erectile activity increased, suggesting a potential role in treating sexual dysfunction¹⁶.

Safety

In clinical studies, PT-141 was well-tolerated in male subjects, as no significant changes occurred in laboratory results or vital signs. The most common side effects included nausea and flushing. Therefore, the safety profile of PT-141 indicates it is a promising option for issues related to sexual dysfunction¹⁷.

References

1. Hormones: What they are, function & types. (n.d.). Cleveland Clinic. Retrieved September 3, 2022, from https://my.clevelandclinic.org/health/articles/22464-hormones
2. Hgh (Human growth hormone): What it is, benefits & side effects. (n.d.). Cleveland Clinic. Retrieved September 3, 2022, from https://my.clevelandclinic.org/health/articles/23309-human-growth-hormone-hgh
3. Ghigo, E., Arvat, E., Muccioli, G., & Camanni, F. (1997). Growth hormone-releasing peptides. European Journal of Endocrinology, 136(5), 445–460. https://doi.org/10.1530/eje.0.1360445
4. Walker, R. F. (2006). Sermorelin: A better approach to management of adult-onset growth hormone insufficiency? Clinical Interventions in Aging, 1(4), 307–308.
5. Thorner, M., Rochiccioli, P., Colle, M., Lanes, R., Grunt, J., Galazka, A., Landy, H., Eengrand, P., & Shah, S. (1996). Once daily subcutaneous growth hormone-releasing hormone therapy accelerates growth in growth hormone-deficient children during the first year of therapy. Geref International Study Group. The Journal of Clinical Endocrinology & Metabolism, 81(3), 1189–1196. https://doi.org/10.1210/jcem.81.3.8772599
6. Khorram, O., Laughlin, G. A., & Yen, S. S. C. (1997). Endocrine and metabolic effects of long-term administration of[ nle 27 ]growth hormone-releasing hormone-(1–29)-nh 2 in age-advanced men and women 1. The Journal of Clinical Endocrinology & Metabolism, 82(5), 1472–1479. https://doi.org/10.1210/jcem.82.5.3943
7. Sermorelin therapy benefits, uses, side effects, risks, more. (2022, April 27). Healthline. https://www.healthline.com/health/sermorelin
8. Https://www. Cancer. Gov/publications/dictionaries/cancer-drug/def/ipamorelin. (2011, February 2). [NciAppModulePage]. https://www.cancer.gov/publications/dictionaries/cancer-drug/def/ipamorelin
9. Gobburu, J. V. S., Agersø, H., Jusko, W. J., & Ynddal, L. (1999). Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharmaceutical Research, 16(9), 1412–1416. https://doi.org/10.1023/A:1018955126402
10. Venkova, K., Mann, W., Nelson, R., & Greenwood-Van Meerveld, B. (2009). Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus. The Journal of Pharmacology and Experimental Therapeutics, 329(3), 1110–1116. https://doi.org/10.1124/jpet.108.149211
11. Teichman, S. L., Neale, A., Lawrence, B., Gagnon, C., Castaigne, J.-P., & Frohman, L. A. (2006). Prolonged stimulation of growth hormone (Gh) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults. The Journal of Clinical Endocrinology and Metabolism, 91(3), 799–805. https://doi.org/10.1210/jc.2005-1536
12. Vukojević, J., Milavić, M., Perović, D., Ilić, S., Čilić, A. Z., Đuran, N., Štrbe, S., Zoričić, Z., Filipčić, I., Brečić, P., Seiverth, S., & Sikirić, P. (2021). Pentadecapeptide BPC 157 and the central nervous system. Neural Regeneration Research, 17(3), 482–487. https://doi.org/10.4103/1673-5374.320969
13. Chang, C.-H., Tsai, W.-C., Hsu, Y.-H., & Su Pang, J.-H. (2014). Pentadecapeptide bpc 157 enhances the growth hormone receptor expression in tendon fibroblasts. Molecules, 19(11), 19066–19077. https://doi.org/10.3390/molecules191119066
14. Xu, C., Sun, L., Ren, F., Huang, P., Tian, Z., Cui, J., Zhang, W., Wang, S., Zhang, K., He, L., Zhang, W., Zhang, C., Hao, Q., Zhang, Y., Li, M., & Li, W. (2020). Preclinical safety evaluation of body protective compound-157, a potential drug for treating various wounds. Regulatory Toxicology and Pharmacology: RTP, 114, 104665. https://doi.org/10.1016/j.yrtph.2020.104665
15. Deek, S. A. (2022). Bpc 157 as potential treatment for covid-19. Medical Hypotheses, 158, 110736. https://doi.org/10.1016/j.mehy.2021.110736
16. Molinoff, P. B., Shadiack, A. M., Earle, D., Diamond, L. E., & Quon, C. Y. (2003). PT-141: A melanocortin agonist for the treatment of sexual dysfunction. Annals of the New York Academy of Sciences, 994, 96–102. https://doi.org/10.1111/j.1749-6632.2003.tb03167.x
17. Diamond, L. E., Earle, D. C., Rosen, R. C., Willett, M. S., & Molinoff, P. B. (2004). Double-blind, placebo-controlled evaluation of the safety, pharmacokinetic properties and pharmacodynamic effects of intranasal PT-141, a melanocortin receptor agonist, in healthy males and patients with mild-to-moderate erectile dysfunction. International Journal of Impotence Research, 16(1), 51–59. https://doi.org/10.1038/sj.ijir.3901139

Author

David J. Bauder, PA-C David Bauder, PA-C, is a certified physician assistant and the assistant medical director at Weight Loss and Vitality in Manassas and Alexandria, Virginia, Washington, DC; and Gaithersburg, MD. He enjoys helping patients optimize their physical and mental health to improve their overall well-being. He earned his physician assistant degree from the University of Texas Health Science Center at San Antonio. Afterward, he gained admission into the reputable graduate program for physician assistant studies at the University of Nebraska Health Science Center in Omaha. David has over 26 years of experience working as a physician assistant. He’s practiced in podiatry, family medicine, emergency medicine, general surgery, urgent care, and functional medicine.