This is a working overview of growth hormone, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-11-29 and is reviewed periodically as new material appears.
Clinical interest in tesamorelin arose from the need to address visceral adiposity in people living with HIV. Antiretroviral therapy improved survival but was associated in some patients with central fat accumulation, altered lipid profiles, and metabolic complications. This condition, often called HIV-associated lipodystrophy, involves excess visceral adipose tissue that is difficult to manage through diet and exercise alone. Investigators evaluated tesamorelin because GHRH analogs can stimulate growth hormone secretion and influence fat distribution without direct liposuction or invasive procedures.
A Phase 3 program led to regulatory approval in the United States in 2010 for reduction of excess visceral abdominal fat in adults with HIV and lipodystrophy. Subsequent studies examined effects on liver fat, muscle area, and metabolic markers, with mixed findings for some endpoints. Long-term cardiovascular outcomes and effects on mortality remain uncertain because most trials were relatively short and focused on imaging-based fat measurements. Use in populations without HIV has been studied experimentally but is not part of the approved indication.
Tesamorelin is a synthetic peptide of forty-four amino acids whose sequence reproduces human growth hormone-releasing hormone. Its distinguishing feature sits at the amino terminus, where a trans-3-hexenoyl group replaces the free amine. That acylation slows cleavage by dipeptidyl peptidase IV, an enzyme that otherwise removes the first two residues and inactivates the natural hormone quickly. The modified peptide therefore persists longer in circulation while keeping the same receptor target. It is handled as a lyophilized solid and dissolved shortly before use.
Signaling begins at the GHRH receptor, a class B G protein-coupled receptor displayed on somatotroph cells of the anterior pituitary. Receptor occupancy activates Gs proteins, which raise adenylyl cyclase activity and intracellular cyclic AMP, in turn driving protein kinase A dependent pathways. The downstream output is synthesis and pulsatile secretion of growth hormone into the bloodstream. Hepatic tissue and peripheral sites respond by increasing insulin-like growth factor 1 production. Somatostatin and IGF-1 itself supply negative feedback that caps the size and duration of each secretory burst.
Metabolic interest in this compound centers on fat distribution rather than on hormone levels alone. Imaging trials in adults with excess abdominal fat report reductions in visceral adipose tissue, while subcutaneous depots change comparatively little. Growth hormone and IGF-1 are presumed to carry the effect, but the separate contribution of each is not firmly established. Whether these changes persist after treatment stops, and whether they alter longer-term health outcomes, remain open questions that published work does not answer consistently.
| Property | Value | Notes |
|---|---|---|
| Molecular weight | Approximately 5,136 Da | Based on the 44-amino-acid peptide backbone and N-terminal modification. |
| Appearance | White to off-white lyophilized powder | Usually supplied in single-use vials for reconstitution. |
| Solubility | Freely soluble in water; slightly soluble in some organic solvents | Peptide nature supports aqueous reconstitution. |
| Typical storage | 2–8 °C, protected from light | Refrigeration reduces degradation; avoid freezing unless specified. |
| Common analytical method | Reverse-phase high-performance liquid chromatography | Used for identity, purity, and quantification. |
| Synonyms | Tesamorelin, TH9507, GHRH(1-44) analog | Generic descriptors; avoid proprietary names. |
Tesamorelin is a synthetic peptide analog of growth hormone-releasing hormone (GHRH). Its sequence corresponds to the 44-amino-acid form of human GHRH with a trans-3-hexenoyl group attached to the N-terminal tyrosine. This modification slows enzymatic cleavage and extends the peptide's activity relative to the native hormone. The compound is produced by solid-phase peptide synthesis and supplied as a lyophilized powder. Researchers classify it as a GHRH receptor agonist. Its structure places it in the same family as other growth hormone secretagogues that act on the pituitary.
Binding of tesamorelin to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and the release of growth hormone into circulation. Because the peptide acts upstream of the growth hormone axis, its effects are partly mediated by hepatic insulin-like growth factor 1 (IGF-1) production. The pulsatile character of endogenous growth hormone secretion is preserved rather than replaced. Whether amplified signaling produces effects beyond those of native GHRH remains an area of ongoing investigation.
A documented effect of tesamorelin is a reduction in visceral adipose tissue in some study populations. Researchers have reported decreases in trunk fat measured by computed tomography alongside changes in lipid markers. The mechanism is thought to involve growth hormone-mediated lipolysis, though the precise contribution of direct versus indirect pathways is not fully resolved. Studies have generally examined defined groups over finite periods, so long-term outcomes are less well characterized. Findings have not been uniform across all trials.
Tesamorelin binds to growth hormone-releasing hormone receptors on the surface of pituitary somatotroph cells. This binding activates adenylate cyclase, raising intracellular cyclic AMP levels and triggering the release of growth hormone into circulation. The elevated growth hormone then stimulates hepatic production of insulin-like growth factor 1. Because the effect is mediated through the endogenous axis, secretion remains subject to feedback regulation. This distinguishes it from direct growth hormone administration, which bypasses pituitary control entirely.
Clinical investigation has focused on HIV-associated lipodystrophy, a condition in which antiretroviral therapy contributes to abnormal fat distribution. Excess visceral adipose tissue accumulates in the abdomen while peripheral fat may be lost. Tesamorelin was evaluated for reducing this visceral fat depot, with trials measuring changes in abdominal fat by imaging rather than by body weight alone. The rationale rests on the known lipolytic effects of growth hormone. Effects on visceral fat are documented, while long-term outcomes regarding cardiovascular risk remain less clearly established.
Platelets play an essential role in clotting. When the wall of a blood vessel is damaged, platelets adhere to the exposed surface at the site of injury and plug the gap. Simultaneous activation of the coagulation cascade results in the formation of fibrin, which reinforces the platelet plug to create a stable clot. A low platelet count, known as thrombocytopenia, may cause bleeding if severe. It can occur in individuals who are undergoing treatments that suppress the bone marrow, such as chemotherapy or radiation therapy, or taking certain drugs, such as heparin, that can induce the immune system to destroy platelets. Thrombocytopenia is a feature of many blood disorders, like acute leukaemia and aplastic anemia, as well as some autoimmune diseases. If the platelet count is extremely low, a platelet transfusion may be performed. Thrombocytosis, meaning a high platelet count, may occur in states of inflammation or trauma, as well as in iron deficiency, and the platelet count may reach exceptionally high levels in people with essential thrombocythemia, a rare blood disease. The platelet count can be reported in units of cells per microlitre of blood (/μL), 103 cells per microlitre (× 103/μL), or 109 cells per litre (× 109/L).
Diazo- und Azoverbindungen der Fettreihe, Barth, Leipzig (1888) Studien mit Hydrazin, Barth, Leipzig, Bd 1,2 (1896), Bd 3,4 (1918) Einwirkung von Basen auf Diazoessigester, Berlin (1911) Die reduktion der aromatische Aldazine und Ketazine, Barth, Leipzig (1912) Hydrazide und Azide der Azidofettsäuren, Berlin (1912) Die Einwirkungen von Hydrazin auf Nitroverbindungen, Barth, Leipzig (1913) Buchner, E.; Curtius, Th. (1885). "Synthese von Ketonsäureäthern aus Aldehyden und Diazoessigäther". Berichte (in German). 18 (2): 2373–2377. doi:10.1002/cber.188501802118. Buchner, E.; Curtius, Th. (1885). "Ueber die Einwirkung von Diazoessigäther auf aromatische Kohlenwasserstoffe". Berichte (in German). 18 (2): 2377–2379. doi:10.1002/cber.188501802119. Curtius, Th. (1890). "Chemische Notizen". Berichte (in German). 23 (2): 3023–3041. doi:10.1002/cber.189002302233. Curtius, Th. (1894). "Hydrazide und Azide organischer Säuren I. Abhandlung". J. Prakt. Chem. (in German). 50 (1): 275–294. doi:10.1002/prac.18940500125.
Cardiac fibroblasts are vital supporting cells within cardiac muscle. They are unable to provide forceful contractions like cardiomyocytes, but instead are largely responsible for creating and maintaining the extracellular matrix which surrounds the cardiomyocytes. Fibroblasts play a crucial role in responding to injury, such as a myocardial infarction. Following injury, fibroblasts can become activated and turn into myofibroblasts – cells which exhibit behaviour somewhere between a fibroblast (generating extracellular matrix) and a smooth muscle cell (ability to contract). In this capacity, fibroblasts can repair an injury by creating collagen while gently contracting to pull the edges of the injured area together. Fibroblasts are smaller but more numerous than cardiomyocytes, and several fibroblasts can be attached to a cardiomyocyte at once. When attached to a cardiomyocyte they can influence the electrical currents passing across the muscle cell's surface membrane, and in the context are referred to as being electrically coupled, as originally shown in vitro and in the 1960s, and ultimately confirmed in native cardiac tissue with the help of optogenetic techniques. Other potential roles for fibroblasts include electrical insulation of the cardiac conduction system, and the ability to transform into other cell types including cardiomyocytes and adipocytes.
Sources: en.wikipedia.org
In February 2018, Teva Pharmaceutical Industries Ltd has completed the sale of a portfolio of products within its global women's health business across contraception, fertility, menopause and osteoporosis for $703 million in cash to CVC Capital Partners Fund VI. Teva also agreed to sell its Plan B One-Step and its brands of emergency contraception to Foundation Consumer Healthcare for $675 million in cash. Combined annual net sales of these products were $140 million last year. It also sold Paragard to a unit of Cooper Companies Inc (COO.N) for $1.1 billion.
== Biosynthesis and occurrence == It is produced in eukaryotic organisms from succinate in complex 2 of the electron transport chain via the enzyme succinate dehydrogenase. Fumaric acid is found in fumitory (Fumaria officinalis), bolete mushrooms (specifically Boletus fomentarius var. pseudo-igniarius), lichen, and Iceland moss. Fumarate is an intermediate in the citric acid cycle used by cells to produce energy in the form of adenosine triphosphate (ATP) from food. It is formed by the oxidation of succinate by the enzyme succinate dehydrogenase. Fumarate is then converted by the enzyme fumarase to malate. Human skin naturally produces fumaric acid when exposed to sunlight. Fumarate is also a product of the urea cycle. Click on genes, proteins and metabolites below to link to respective articles.
=== In prokaryotes === In prokaryotes a small 30S ribosomal subunit contains the 16S ribosomal RNA. The large 50S ribosomal subunit contains two rRNA species (the 5S and 23S ribosomal RNAs). Therefore it can be deduced that in both bacteria and archaea there is one rRNA gene that codes for all three rRNA types :16S, 23S and 5S. Bacterial 16S ribosomal RNA, 23S ribosomal RNA, and 5S rRNA genes are typically organized as a co-transcribed operon. As shown by the image in this section, there is an internal transcribed spacer between 16S and 23S rRNA genes. There may be one or more copies of the operon dispersed in the genome (for example, Escherichia coli has seven). Typically in bacteria there are between one and fifteen copies. Archaea contains either a single rRNA gene operon or up to four copies of the same operon. The 3' end of the 16S ribosomal RNA (in a ribosome) recognizes a sequence on the 5' end of mRNA called the Shine-Dalgarno sequence.
Sources: en.wikipedia.org
It is a synthetic peptide analog of human growth hormone-releasing hormone. It is used clinically to reduce excess visceral abdominal fat in adults with HIV-associated lipodystrophy. It works by stimulating pituitary growth hormone release.
Pivotal trials enrolled adults with HIV and excess visceral abdominal fat, often in the context of antiretroviral therapy. Participants were assessed mainly by computed tomography for visceral adipose tissue. The approved indication remains specific to that population.
Long-term effects on cardiovascular events, mortality, and sustained fat distribution are not well established. Most trials measured changes over months rather than years. Open questions also include whether benefits persist after treatment stops.
The amino acid sequence matches human growth hormone-releasing hormone, but the amino terminus carries a trans-3-hexenoyl group instead of a free amine. That single structural change chiefly affects enzymatic stability rather than receptor selectivity.