Peptides and Their Effects on Our Body

Therapeutic peptides are relatively short chains of amino acids that constitute a class of pharmaceutical agents. These include the naturally occurring human hormones insulin, vasopressin, and oxytocin. The discovery of insulin in 1921 and commercialized as a drug for controlling blood sugar in diabetics was ground-breaking and saved and enhanced the lives of countless individuals. More peptides were developed in the second half of the 20^th century, including synthetic versions of oxytocin, vasopressin, and insulin. A total of 34 peptide drugs have been approved world-wide in the 21^st century to date. This includes peptide molecules used to treat HIV, chronic pain, and type 2 diabetes. Newer peptide have been discussed in the lay press that have been touted to help build muscle and shed body fat. In some cases these peptides have been touted as geroprotective “fountains of youth.” Are they?

Many people complain of a variety of changes as they age, including weight gain, loss of muscle mass, brain fog, poor sleep, fatigue, and a decrease in libido. Hormones that diminish in the body as we age include human growth hormone (HGH). HGH administration has been associated with improvement in all of these areas, prompting it being pitched as an anti-aging remedy. A variety of peptides that stimulate HGH secretion are available; their use is called “Growth hormone stimulating peptide therapy.” Two common peptides offered are CJC-1295,  Sermorelin, Tesamorelin, and Ibutamoren.

There are several down sides of using HGH-stimulating peptides. These include insulin resistance, potentially leading to type 2 diabetes; joint and muscle swelling and pain; increased risk of certain cancers; and enlargement of breast tissue in men. I have discussed the significant health benefits of low-grade metabolic stress on healthy longevity (see article on hormesis). Taking peptides that increase HGH levels essentially is the opposite of hormesis. While the latter is an example of “what doesn’t kill you makes you stronger,” the former is “too much of a good thing.” Although there is no proven benefit of these peptides, HGH is on the World Anti-Doping Agency (WADA) Prohibited List, i.e. athletes found to be using it are banned from competition which means athletes found to use it are banned from competition.

The bottom line: unless you have a documented deficiency of HGH and are under a doctor’s care for this, peptides that stimulate HGH secretion, like HGH itself, should not be used.

Note: Although I am a physician, the content in this article is not meant to diagnose, treat, cure or prevent illness or disease in the reader – it is for educational purposes only.

References

• Wang L, Wang N, Zhang W, et al. Therapeutic peptides: current applications and future directions. Signal Transduction and Targeted Therapy (2022) 7:48
• Mathieu, C., Gillard, P. & Benhalima, K. Insulin analogues in type 1 diabetes mellitus: getting better all the time. Nat. Rev. Endocrinol. 13, 385–399 (2017).
• Ghigo E, Arvat E, Muccioli, Camanni F. Growth hormone-releasing peptides. Eur J Endocrino 1997;136(5):445-60.