A practical reference on IGF-1: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-12-20. Anything still debated is marked as such rather than presented as settled.
Tesamorelin is a synthetic peptide that belongs to the growth hormone-releasing hormone (GHRH) family. Its sequence corresponds to the fully active 44-amino-acid form of human GHRH, with a single structural modification: the addition of a trans-3-hexenoyl group at the N-terminus. That modification is not found in the naturally occurring hormone and was introduced deliberately during development to improve stability against enzymatic degradation. The compound is therefore best described as a stabilized analogue rather than a naturally occurring peptide.
The native hormone is produced in the hypothalamus and acts on the anterior pituitary. Binding of GHRH to its receptor stimulates synthesis and release of growth hormone into circulation. Because the analogue retains the receptor-binding region of the parent sequence, it engages the same receptor and triggers the same downstream signaling. The result is increased growth hormone secretion from pituitary cells, which in turn influences hepatic production of insulin-like growth factor 1. This axis is the basis for the compound's measured biological effects.
Interest in this peptide developed because native GHRH has a short circulating lifetime. The N-terminal modification slows cleavage by dipeptidyl peptidase IV, an enzyme that removes the first two residues of many peptides and terminates their activity. Slower degradation means a longer window of receptor stimulation per administration. This design logic parallels other modified peptide hormones, where a small chemical change at a vulnerable site yields a more durable molecule without altering the core mechanism of action.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C221H366N72O67S | Reflects a 44-residue peptide with one N-terminal modification |
| Approximate molecular weight | 5136 Da | Sequence length and single acyl group determine the mass |
| Appearance | White to off-white lyophilized powder | Typical form of a purified synthetic peptide |
| Solubility class | Soluble in water and aqueous buffer | Peptide backbone favors aqueous dissolution |
| Common synonyms | GHRH(1-44) analogue; Egrifta | Descriptive name and approved brand name |
Tesamorelin is a synthetic peptide that belongs to the growth hormone-releasing hormone family and contains the same forty-four amino acid sequence as endogenous GHRH, extended at the amino terminus by a trans-3-hexenoyl group. That small fatty acid modification protects the peptide from rapid cleavage by dipeptidyl peptidase-4, the enzyme that shortens the half-life of native GHRH to only a few minutes. Chemically the compound is produced by solid-phase peptide synthesis, purified by chromatography, and supplied as a sterile lyophilized powder for reconstitution.
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.
=== The Copa América final (1975) === The renamed and decentralised 1975 Copa América produced Colombia's first deep run in a continental tournament. Coached by Efraín Sánchez, the goalkeeper of the 1962 squad, Colombia won all four group matches against Paraguay and Ecuador, scoring seven and conceding one. In the semi-final they overwhelmed the defending champions Uruguay 3–0 at the Estadio El Campín through Edgar Angulo, Ortiz and Ernesto Díaz; the return at the Estadio Centenario finished 1–0 to Uruguay, whose Fernando Morena converted an early penalty before being sent off and whose team missed two further spot-kicks. With the sides level on points, Colombia advanced on goal difference. The final against Peru was the first in the competition's history to be decided over multiple legs. Ponciano Castro settled the opening match in Bogotá on 16 October with a long-range strike; Peru answered a week later at the Estadio Nacional in Lima, Juan Carlos Oblitas and Oswaldo Ramírez scoring inside the first half for a 2–0 win that levelled the tie on points and forced a decider on neutral ground. At the Estadio Olímpico in Caracas on 28 October, Hugo Sotil — flown in from Barcelona — scored the only goal before 30,000 spectators, and Peru claimed a second continental title. Ernesto Díaz finished as the tournament's joint leading scorer with four goals, a total that still ranks among the highest by a Colombian at the Copa América.
Non-prescription topical products that have health claims for reducing facial acne, combating skin dark spots and reducing wrinkles and lines associated with aging often contain retinyl palmitate. The hypothesis is that this is absorbed and de-esterified to free retinol, then converted to retinaldehyde and further metabolized to all-trans-retinoic acid, whence it will have the same effects as prescription products with fewer side effects. There is some ex vivo evidence with human skin that esterified retinol is absorbed and then converted to retinol. In addition to esterified retinol, some of these products contain hydroxypinacolone retinoate, identified as esterified 9-cis-retinoic acid.
The Napoleonic Wars (1803–1815) were a global series of conflicts fought by a fluctuating array of European coalitions against the French First Republic (1803–1804) under the First Consul followed by the First French Empire (1804–1815) under the Emperor of the French, Napoleon. The wars originated in political forces arising from the French Revolution (1789–1799) and French Revolutionary Wars (1792–1802) and produced a period of French domination over continental Europe. The wars are categorised as seven conflicts, five named after the coalitions that fought Napoleon, plus two named for their respective theatres: the War of the Third Coalition, War of the Fourth Coalition, War of the Fifth Coalition, War of the Sixth Coalition, War of the Seventh Coalition, the Peninsular War, and the French invasion of Russia. The first stage of the wars broke out when Britain declared war on France on 18 May 1803. After minor campaigns, Britain allied with Austria, Russia, and minor powers, to form the Third Coalition in April 1805. Napoleon defeated the allied Russo-Austrian armies in the subsequent war which climaxed in French victories at Ulm and at Austerlitz, leading to the dissolution of the Holy Roman Empire and Austria being forced to make peace. Britain and Russia remained at war with France. Concerned about increasing French power, Prussia joined Britain and Russia in the Fourth Coalition, which resumed war in October 1806.
Sources: en.wikipedia.org
==== Inert ==== Inert IUDs are not approved for use in the United States, the UK, or Canada. Inert IUDs do not have a bioactive component. They are made of inert materials such as stainless steel or plastic. Their primary mechanism of action is to cause a local foreign body reaction, which makes the uterine environment hostile to both sperm and implantation. They may have higher rates of preventing pregnancy after fertilization, instead of before fertilization, compared to copper or hormonal IUDs.
In the establishment of the Soviet Union in the former Russian Empire, Bolshevism was the ideological basis. As the only legal vanguard party, it decided almost all policies, which the communist party represented as correct. Because Leninism was the revolutionary means to achieving socialism in the praxis of government, the relationship between ideology and decision-making inclined to pragmatism and most policy decisions were taken in light of the continual and permanent development of Marxism–Leninism, with ideological adaptation to material conditions. The Bolshevik Party lost in the 1917 Russian Constituent Assembly election, obtaining 23.3% of the vote, to the Socialist Revolutionary Party, which obtained 37.6%. On 6 January 1918, the Draft Decree on the Dissolution of the Constituent Assembly was issued by the Central Executive Committee of the Congress of Soviets, a committee dominated by Vladimir Lenin, who had previously supported multi-party free elections. After the Bolshevik defeat, Lenin started referring to the assembly as a "deceptive form of bourgeois-democratic parliamentarism". This was criticised as being the development of vanguardism as a form of hierarchical party–elite that controlled society. Within five years of the death of Lenin, Joseph Stalin completed his rise to power and was the leader of the Soviet Union who theorised and applied the socialist theories of Lenin and Karl Marx as political expediencies used to realise his plans for the Soviet Union and for world socialism.
== Applications == As a positron emitter, 64Cu has been used to produce experimental and clinical radiopharmaceuticals for the imaging of a range of conditions. Its beta emissions also raise the possibility of therapeutic applications. Compared to typical PET radionuclides it has a relatively long half-life, which can be advantageous for therapy, and for imaging certain physiological processes.
Sources: en.wikipedia.org
In November 2024, the US Food and Drug Administration approved PropofolVet Multidose, the first generic propofol injectable emulsion for dogs. PropofolVet Multidose is approved for use as an injectable anesthetic in dogs. PropofolVet Multidose contains the same active ingredient (propofol injectable emulsion) as the approved brand-name drug product, PropoFlo 28, which was first approved on 4 February 2011. In addition, the FDA determined that PropofolVet Multidose contains no inactive ingredients that may significantly affect the bioavailability of the active ingredient.
Nucleic acid analogues are compounds which are structurally analogous to naturally occurring RNA and DNA, through substitutions of any of its sugar, phosphate, and nucleobase components. They are used in medicine and in molecular biology research.
==== Thermoregulation ==== Hair length is not a factor in thermoregulation: for example, some tropical mammals such as sloths have the same length of fur length as some arctic mammals but with less insulation; and, conversely, other tropical mammals with short hair have the same insulating value as arctic mammals. The denseness of fur can increase an animal's insulation value, and arctic mammals especially have dense fur; for example, the musk ox has guard hairs measuring 30 cm (12 in) as well as a dense underfur, which forms an airtight coat, allowing them to survive in temperatures of −40 °C (−40 °F). Some desert mammals, such as camels, use dense fur to prevent solar heat from reaching their skin, allowing the animal to stay cool; a camel's fur may reach 70 °C (158 °F) in the summer, but the skin stays at 40 °C (104 °F). Aquatic mammals, conversely, trap air in their fur to conserve heat by keeping the skin dry.
Sources: en.wikipedia.org
It shares the 44-residue sequence of human GHRH but carries an added trans-3-hexenoyl group at its N-terminus. That addition does not occur in the natural hormone and serves mainly to resist enzymatic breakdown. The receptor target and signaling pathway remain the same.
It binds the growth hormone-releasing hormone receptor on anterior pituitary cells. Activation of that receptor promotes synthesis and release of growth hormone. The effect propagates through the growth hormone and insulin-like growth factor 1 axis.
Native GHRH is cleared quickly by peptidases, which limits how long it can stimulate its receptor. The added group hinders one of the primary cleavage enzymes. The practical consequence is a longer period of receptor activity per dose.
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.