Tesamorelin is an analogue of GHRH (growth hormone releasing hormone, a naturally-occurring peptide released from the hypothalamus) that was recently approved by the FDA
Tesamorelin is an analogue of GHRH (growth hormone releasing hormone, a naturally-occurring peptide released from the hypothalamus) that was recently approved by the FDA for treatment (reduction) of HIV-induced lipodystrophy-related visceral fat and is now marketed under the trade name Egrifta. Like GHRH, tesamorelin exerts its effects through inducing GH release from the pituitary.
Tesamorelin has a wide variability of pharmacokinetics among individuals. The recommended and best-studied dose is 2mg dosed weekly or daily. It has been demonstrated to have low oral bioavailability and is dosed subcutaneously.
Lipodystrophy is the medical term for a condition characterized by the abnormal condition of fat deposits, specifically lipoatrophy in most cases. In HIV-induced lipodostrophy sometimes normal fat deposits, such as those that give the face its shape, shrink and atrophy while others can grow and pose a risk to patient health. One such example of unhealthy fat deposits is visceral adipose tissue.
Visceral adipose tissue (VAT) refers to fat deposits that are located in the abdomen, but unlike subcutaneous (beneath the skin) deposits, are actually deeper and reside between organs. It is sometimes referred to as “intra-organ” fat. VAT is itself associated with a variety of negative effects:
Visceral fat (VF) accretion is a hallmark of aging in humans. Epidemiologic studies have implicated abdominal obesity as a major risk factor for insulin resistance, type 2 diabetes, cardiovascular disease, metabolic syndrome and death.
The purpose of the study by Huffman and Barzilai, cited above, was to zero in on the link between VF and mortality. The limitations of epidemiological studies makes it difficult to determine causality. They found that “Specific depletion or expansion of the VF depot using genetic or surgical tools in rodents has been shown to have direct effects on disease risk” while the same was not true of SC fat deposits.
In a medium-scale (400 patient) randomized clinical trial where patients were randomly selected to receive 2mg subcutaneous tesamorelin for 52 weeks, placebo for 52 weeks, or 26 weeks of each, tesamorelin reduced visceral adipose tissue by 18% and triglyceride scores improved. The incidence of adverse effects and serious adverse effects were low. Glucose tolerance was not negatively affected. When GH is used for medium or long periods of time, fasted glucose levels and insulin sensitivity are negatively affected[4,5].
Tesamorelin and other GH secretagogues may be of use in treating excess visceral adipose tissue in otherwise-healthy subjects, as was the focus of a study by Stanley, Chen, et al: “Strategies to augment pulsatile GH may be beneficial in patients with excess visceral adiposity, in whom GH secretion is reduced”. Primary endpoint was overnight GH release as determined by frequent sampling, and secondary endpoints were insulin sensitivity as determined by insulin-stimulated glucose uptake, and GH secretion measures including pulse area and pulse frequency compared to basal secretion. The trial lasted 2 weeks and dosing was 2mg subcutaneously once weekly. The GH parameters were found to increase versus basal secretion, and insulin sensitivity was preserved.
 Patel A, Gandhi H, Upaganlawar A, Tesamorelin: A hope for ART-induced lipodystrophy. Journal of Pharmacy and Bioallied Sciences.
 Huffman DM, Barzilai N, Role of Visceral Adipose Tissue in Aging. Oct 2009; 1790(10):1117-23.
 Falutz J, Allas S, Mamputu JC, et al. Long-term safety and effects of tesamorelin, a growth hormone-releasing factor analogue, in HIV patients with abdominal fat accumulation. AIDS. Sep 2008 12:22(14):1719-28.
 Liang L et al. [Effect of recombinant human growth hormone on glucose metabolism in children with growth hormone deficiency – trans. Chinese]. Zhonghua Er Ke Za Zhi. 2006 Sep;44(9):657-61.
Butler G, Carel JC. Safety of recombinant human growth hormone. Endocr. Dev. 2010;18:40-54.
 Stanley TL, Chen CY, Branch KL, et al. Effects of a growth hormone-releasing analog on endogenous GH pulsatility and insulin sensitivity in healthy men. J Clin Endocrinol Metab. 2011 Jan; 96(1):150-8.