The short version of IGF-1 fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-11-24. Anything still debated is marked as such rather than presented as settled.
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.
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.
Clinical study of tesamorelin has centered on adults with HIV-associated lipodystrophy, a condition in which abdominal fat accumulates while peripheral fat is lost. In controlled trials, treated participants showed reductions in visceral adipose tissue measured by imaging, alongside modest shifts in some lipid values. Effects on subcutaneous fat were smaller and less consistent across studies. Whether these changes translate into fewer cardiovascular events remains an open question, because the trials were not designed or powered to answer it.
Tesamorelin is a synthetic peptide that acts as an analog of growth hormone-releasing hormone, a natural hypothalamic signal. Its sequence corresponds to the forty-four amino acid form of the human hormone, with a small acyl group attached near the amino terminus. That modification slows enzymatic breakdown and extends the time the peptide remains active in circulation. The compound was developed as a pharmacological way to raise endogenous growth hormone output rather than supplying the hormone directly.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic 44-residue peptide | GHRH analog backbone |
| Approximate molecular mass | 5136 Da | Varies with counterion and hydration state |
| N-terminal group | trans-3-hexenoyl | Increases resistance to dipeptidyl peptidase IV |
| Primary receptor | GHRH receptor (GHRHR) | Class B G protein-coupled receptor on somatotrophs |
| Principal mediator | IGF-1 | Rises indirectly after growth hormone release |
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.
Several related peptides act on the same receptor, including sermorelin, a shorter GHRH fragment, and modified analogs such as CJC-1295 and modified GRF(1-29) that are common in research settings rather than approved products. Tesamorelin differs from growth hormone itself in that it acts upstream, prompting the pituitary to release the hormone through physiological signaling rather than supplying it directly. Terminology in the literature distinguishes GHRH analogs, growth hormone secretagogues, and recombinant growth hormone, although popular discussion often blurs these categories together. Precise naming matters when comparing study results.
Tesamorelin is a synthetic peptide of 44 amino acids that reproduces the sequence of human growth hormone-releasing hormone (GHRH) and carries a trans-3-hexenoyl group on its N-terminal tyrosine. That small fatty-acid modification blocks cleavage by dipeptidyl peptidase-4, the enzyme that rapidly degrades native GHRH in plasma. The result is a molecule with a longer circulating half-life than the natural hormone while retaining the same receptor target. It is supplied as a lyophilized powder for reconstitution and belongs to the broader class of GHRH analogs studied for effects on pituitary growth hormone secretion.
Regulatory approval in the United States came in 2010, when the Food and Drug Administration cleared the peptide for the reduction of excess abdominal fat in adults with HIV infection and associated lipodystrophy. The decision rested mainly on two randomized phase 3 trials that enrolled roughly eight hundred patients and ran for twenty-six weeks. Participants receiving active drug showed substantially greater declines in visceral adipose tissue than those receiving placebo, while total body weight changed comparatively little. A reformulated presentation was later approved, and the product has remained a niche therapy rather than a general weight-loss agent.
Tesamorelin occupies a narrow position among agents that act on the growth hormone axis. Unlike growth hormone itself, which is given as replacement, it stimulates the pituitary to release the hormone in pulses, so the downstream increase in insulin-like growth factor 1 depends on intact somatotroph function. Other peptides in the same family include shorter GHRH fragments and synthetic secretagogues with different stability profiles. Several points remain unresolved, including whether the reduction in visceral fat translates into fewer cardiovascular events, what happens to metabolic markers after long-term use, and how the drug compares with lifestyle or surgical approaches.
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 analog of growth hormone-releasing hormone, a peptide hormone produced by the hypothalamus. The molecule retains the 44-amino-acid sequence of human GHRH and carries a trans-3-hexenoyl modification at its N-terminus. This modification increases resistance to enzymatic degradation and extends the peptide's functional stability relative to native GHRH. The compound is supplied as a lyophilized powder for reconstitution and subcutaneous administration in clinical settings. Its development code was TH9507, and it belongs to the GHRH analog class. It is not a growth hormone product; instead, it acts upstream to stimulate endogenous growth hormone release.
=== Debate over origins === Murdijati Gardjito, a food historian at Gadjah Mada University, argued that tempeh was made by native Javanese people and that its preparation predates the introduction of Chinese-style tofu products. Some ancient texts mention tempe dhele, old Javanese for 'native soybean tempeh'; dhele was used to refer to the native soybean variety. White soybeans that are used to make most tempe dhele today used to be called dhele putih ('white soybeans'), and were only available in Java centuries later. Mary Astuti, a food historian at Gadjah Mada University specializing in tempeh, argued that the native variety of soybean had been grown before the Chinese arrived in the region. Sri Tandjung noted that Javanese had been eating cooked (native black) soybeans since the 12th century. By the 16th or the 19th century, depending on which period of time the writer of Serat Centhini referred to, Javanese people had mastered the art of cooking with tempeh, when it was not only eaten as is, but converted into different types of dishes, showing a full understanding and mastery of the food product. Gardjito noted that Javanese noble families rarely wrote about tempeh in ancient texts because it had never been a part of royal cuisine, but rather a staple food of the lower classes. Indonesian historian Ong Hok Ham suggests that tempeh might have been produced as a byproduct of tahu, the Indonesian word for tofu.
In spite of the political divisions, the four territories were strongly linked. Each was populated by European-African emigrants from the Cape; many citizens had relatives or friends in other territories. As the largest and oldest state in Southern Africa, the Cape was economically, culturally, and socially dominant; the population of Natal and the two Boer republics were mostly subsistence farmers. The fairly simple agricultural dynamic was upset in 1870, when vast diamond fields were discovered in Griqualand West, around modern-day Kimberley. Although the territory had historically come under the authority of the Orange Free State, the Cape government, with the assistance of the British government, annexed the area.
At least 18 microbial VOCs (MVOCs) have been characterized including 1-octen-3-ol (mushroom alcohol), 3-Methylfuran, 2-pentanol, 2-hexanone, 2-heptanone, 3-octanone, 3-octanol, 2-octen-1-ol, 1-octene, 2-pentanone, 2-nonanone, borneol, geosmin, 1-butanol, 3-methyl-1-butanol, 3-methyl-2-butanol, and thujopsene. The last four are products of Stachybotrys chartarum, which has been linked with sick building syndrome.
Subsequently, some defensins can aggregate to form 'channel-like' pores; others might bind to and cover the microbial membrane in a 'carpet-like' manner. The net outcome is the disruption of membrane integrity and function, which ultimately leads to the lysis of microorganisms. Some defensins are synthesized as propeptides which may be relevant to this process. Alpha defensins of the mouse bowel were historically called cryptdins when first discovered.
Counter-Strike was the most successful, having been released in six different editions: as a standalone product (2000), as part of the Platinum Pack (2000), as an Xbox version (2003), and as a single-player spin-off, Counter-Strike: Condition Zero (2004), as well as in two versions using the Source engine. Team Fortress Classic, Day of Defeat, Gunman Chronicles (2000, a futuristic Western movie-style total conversion with emphasis on its single-player mode) and Sven Co-op were also released as standalone products. Half-Life is also the subject of the YouTube improv roleplaying series Half-Life VR but the AI is Self-Aware and Freeman's Mind. In 2003, Valve's network was infiltrated by hackers. Among the stolen files was the unreleased Half-Life mod Half-Life: Threewave, a canceled remake of the Quake mod Threewave CTF. The files were found by fans on a Vietnamese FTP server in February 2016 and unofficially distributed that September.
Sources: en.wikipedia.org
=== Syphilis === Cardiolipin from a cow heart is used as an antigen in the Wassermann test for syphilis. Anti-cardiolipin antibodies can also be increased in numerous other conditions, including systemic lupus erythematosus, malaria and tuberculosis, so this test is not specific.
=== 1980–2009: Expansion globally === As the Japanese economy worsened in the 1980s, Ajinomoto sought to outsource more of its production overseas, which increased the number of employees the company employed overseas from 4,000 in 1979 to more than 11,000 in 1996. Starting in 1980, Ajinomoto began to refocus its diversification efforts from food products to its amino acid business. Following the US FDA's re-approval of aspartame in 1981, Ajinomoto began producing the sweetener at its Tokai factory in 1982. In 1987, Ajinomoto began researching drug development in the fields of clinical nutrition, anti-cancer drugs, infectious diseases, and cardiovascular drugs. Through this research, the company developed ELENTAL for use in clinical nutrition, LIVACT to fight liver disease, and Lentinan in collaboration with the Japanese Foundation for Cancer Research. Ajinomoto later released JINO as a cosmetic and amino acid for athletes, followed by Amino Vital, a supplement to JINO released in 1995. In 2000, Ajinomoto acquired NutraSweet and Euro-Aspartame from Monsanto. In December 1995, Ajinomoto's Philippine CEO and President Leonardo K. Ty was assassinated by two members of the communist guerrilla group Alex Boncayao Brigade. The group cited Ty's allegedly poor safety standards for one of his other companies that they claimed to have led to the deaths of several of his employees. Ty had been head of Union Ajinomoto Inc. with his brother Alejandro since the late 1960s, and prior to his death, Ty had been seeking the protection of the National Bureau of Investigation.
Unidirectional chiral inversion (enzyme mediated) was described only with 2-arylpropionate nonsteroidal anti-inflammatory drugs (NSAIDs), namely ibuprofen, ketoprofen, fenoprofen, benoxaprophen, etc. For this group, only S-enantiomer (eutomer) is active i.e. has analgesic and anti-inflammatory effect. In the body, only inactive R-enantiomer can undergo chiral inversion by hepatic enzymes into the active S-enantiomer and not vice versa. The “inactive” R-isomer (distomer) may be responsible for the gastrointestinal irritation and related side-effects associated with NSAIDs. In certain situations, carbenicillin, ethiazide, etoposide, zopiclone, pantoprazole, clopidogrel, ketorolac, albendazole-sulfoxide, lifibrol, and 5-aryl-thiazolidinedione also go through unidirectional chiral inversion. Chiral inversions were found to happen in a group of important compounds called α-amino acids. Amino acids exist in two mirror-image versions (D- and L- configurations). Several D-amino acids, like D-methionine, D-proline, D-serine, D-alanine, D-aspartate, D-leucine, and D-phenylalanine, have been shown to go through unidirectional chiral inversion in mammals. Bidirectional chiral inversion or racemization type of inversion is shown by pharmaceutical drugs including 3-hydroxy-benzodiazapine class of drugs (Oxazepam, lorazepam, temazepam), thalidomide, and tiaprofenic acid. A brief list of select pharmaceutical drugs that go through chiral inversion are presented in Table below..
=== Mechanism === Natriuretic peptides and their receptors have many different effects on the body, such as controlling blood pressure and helping bones grow. Each peptide has its own unique effects and interacts with specific receptors. Scientists have observed these effects by studying mice with specific natriuretic peptides or receptors removed. Natriuretic peptides have a wide range of physiological effects that include the regulation of blood pressure, fluid and electrolyte balance, and cardiovascular function. They are also involved in the regulation of vascular remodeling, inflammation, and apoptosis. One of the major clinical applications of natriuretic peptides is the diagnosing and managing of heart failure. Elevated levels of ANP and BNP are commonly found in patients with heart failure and can be used as biomarkers for the diagnosis and prognosis of this condition.
Sources: en.wikipedia.org
== Physiological effects == Maintenance of the ECF volume (space), and its subcompartment the vascular space, is crucial for survival. These compartments are maintained within a narrow range, despite wide variations in dietary sodium intake. There are three volume regulating systems: two salt saving systems, the renin angiotensin aldosterone system (RAAS) and the renal sympathetic system (RSS); and the salt excreting natriuretic peptide (NP) hormone system. When the vascular space contracts, the RAAS and RSS are "turned on"; when the atria expand, NPs are "turned on". Each system also suppresses its counteracting system(s). NPs are made in cardiac, intestinal, renal, and adrenal tissue: ANP in one of a family of cardiac NPs: others are BNP, CNP, and DNP. ANP binds to a specific set of receptors – ANP receptors. Receptor-agonist binding causes the increase in renal sodium excretion, which results in a decreased ECF and blood volume. Secondary effects may be an improvement in cardiac ejection fraction and reduction of systemic blood pressure.
Due to the neurotoxicity of its metabolite, norpethidine, it is more toxic than other opioids—especially during long-term use. The norpethidine metabolite was found to have serotonergic effects, so pethidine could, unlike most opioids, increase the risk of triggering serotonin syndrome.
Aerogels are produced by extracting the liquid component of a gel through supercritical drying or freeze-drying. This allows the liquid to be slowly dried off without causing the solid matrix in the gel to collapse from capillary action, as would happen with conventional evaporation. The first aerogels were produced from silica gels. Kistler's later work involved aerogels based on alumina, chromia, and tin dioxide. Carbon aerogels were first developed in the late 1980s.
== External links == FDA Public Health Advisory for Telithromycin (marketed as Ketek) Article in Annals of Internal Medicine regarding cases of hepatotoxicity induced by telithromycin New York Times article. Login is required FDA officials question safety of antibiotic 'Ketek' Drugs and Treatments - KETEK Oral - Patient Handout from WebMD
Furthermore, early outgrowth cells maintain other monocyte functions such as high Dil-Ac-LDL and India ink uptake and low eNOS expression. These original, early outgrowth, CFU-Hill or CACs are also shown to express CD14, a lipopolysaccharide receptor expressed by monocytes but not endothelial cells. Endothelial colony forming cells represent a distinct population that has been found to have the potential to differentiate and promote vessel repair. ECFCs are now known to be tissue-resident progenitor cells in adults that maintain some vasculogenic ability.
Sources: en.wikipedia.org
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.
Growth hormone released from the pituitary stimulates IGF-1 production in the liver and other tissues, so circulating IGF-1 generally rises during exposure. The size of the rise varies between individuals and depends on baseline hormonal status and other concurrent factors.
Reported imaging studies focus on visceral adipose tissue, where reductions are more consistently observed across trials. Subcutaneous depots show smaller and less reproducible changes, so the two compartments should not be treated as equivalent.
It is a laboratory-made peptide that mimics growth hormone-releasing hormone. It prompts the pituitary gland to release growth hormone and has been studied mainly in adults with HIV-associated lipodystrophy.