This is a working overview of GHRH analogue, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-09-27. Anything still debated is marked as such rather than presented as settled.
CJC-1295 is a synthetic peptide designed as a long-acting analogue of growth hormone-releasing hormone (GHRH). Its structure derives from the first 29 amino acids of native GHRH, a fragment often called GRF(1-29). Four substitutions were introduced to slow enzymatic breakdown and extend activity relative to the natural sequence. The compound was developed by ConjuChem as part of a broader effort to improve the pharmacokinetic profile of peptide hormones. It is studied in laboratory and clinical research settings rather than appearing as a naturally occurring substance.
Two related forms circulate in technical discussion under the same family name. The original version carries a drug affinity complex (DAC) that binds covalently to serum albumin after administration, and this linkage substantially extends circulation time. A second form, frequently written as modified GRF(1-29) or CJC-1295 without DAC, lacks that linker and clears much faster. The naming is a frequent source of confusion because the shorthand CJC-1295 can refer to either form depending on the source. Reports sometimes fail to specify which variant was studied.
The peptide backbone includes a D-alanine at position two, which resists cleavage by dipeptidyl peptidase IV, and several other substitutions that reduce degradation. Its molecular weight is roughly 3.4 kDa without the linker and about 3.6 kDa with it. The molecule is water soluble and is normally supplied as a lyophilized powder. Precise sequence and mass values depend on which variant is described, so technical documents usually state the exact form being referenced.
Clearance profiles diverge sharply between the two versions. The albumin-binding molecule stays in plasma for several days, whereas the unmodified analog is largely gone within about half an hour in reported work. Cleavage by dipeptidyl peptidase IV is a major contributor to the short life of the unmodified sequence. These gaps mean the two versions cannot be substituted for each other in study design or in reading results side by side.
Reports on this compound commonly follow serum growth hormone and insulin-like growth factor 1 across defined time windows. Protocols differ in sampling frequency, assay platform, and participant characteristics, which makes direct comparison between publications difficult. Some work focuses on pulsatile release patterns instead of average concentrations. Whether repeated exposure alters endogenous hormone rhythms over long periods remains an open question, and the formal literature is thinner than the volume of informal commentary implies.
| Property | Value | Notes |
|---|---|---|
| Molecular weight (no linker) | ~3.37 kDa | Calculated from peptide sequence |
| Molecular weight (with linker) | ~3.65 kDa | Includes albumin-binding moiety |
| Appearance | White to off-white powder | Typically lyophilized |
| Solubility | Soluble in water | Also dissolves in aqueous buffers |
| Common synonyms | Modified GRF(1-29), DAC:GRF | Usage varies by source |
Downstream of growth hormone, the liver and other tissues increase production of insulin-like growth factor 1, a mediator of many growth-promoting effects. Studies have documented elevated levels of both hormones after dosing, and the rise from the long-acting form persists longer than that produced by shorter-acting analogues. What remains unclear is whether sustained elevation of these markers translates into meaningful clinical benefit, and whether prolonged exposure carries risks that short trials could not detect.
CJC-1295 acts at the growth hormone-releasing hormone receptor, a G-protein-coupled receptor found on somatotroph cells in the anterior pituitary. Binding triggers a rise in cyclic AMP and calcium entry, which promotes release of stored growth hormone. Because the peptide mimics the body's own releasing hormone, it amplifies existing secretory pulses rather than driving continuous output. The size of the response therefore depends partly on the subject's own hormonal rhythm and feedback state.
The attached maleimide group explains the unusual duration of the DAC version. After injection it reacts with the thiol of cysteine-34 on serum albumin, forming a stable covalent bond. The resulting conjugate is too large for rapid kidney filtration and is shielded from many peptidases. Reported half-lives for this form reach several days, whereas the version without the group is cleared in roughly half an hour. That gap is the main pharmacological difference between the two.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography combined with mass spectrometry. The chromatographic separation resolves the target peptide from truncation products and from species carrying oxidised residues, while mass measurement confirms the expected molecular mass. Because the two common variants differ by roughly 280 daltons, a mass determination distinguishes them unambiguously. Purity is often quoted as a percentage of total peak area, although that figure depends on the detection wavelength and the integration method applied.
Reported half-lives differ widely between the two variants and between species. Values for the albumin-binding form are usually expressed in days, while the unconjugated form is measured in minutes to a few hours. Sampling schedules, assay sensitivity, and route of administration all influence the numbers, which limits direct comparison across studies. Whether sustained receptor occupancy produces different downstream effects from pulsatile stimulation remains an open question in the published work. Claims about relative potency should therefore be read alongside the specific study design that produced them.
Binding of the peptide to the growth hormone-releasing hormone receptor on pituitary somatotrophs triggers a G protein coupled cascade that raises cyclic AMP and opens calcium channels. The result is greater secretion of growth hormone into the bloodstream. Because the peptide acts at the same receptor as the natural hypothalamic hormone, its effect is amplified pulse size rather than an entirely separate release pathway. Receptor binding alone does not determine the response, since somatostatin tone and other inputs modulate the final output.
The albumin-binding version stays in circulation for days, because covalent attachment to serum albumin shields the peptide from rapid filtration and degradation. Reported half-lives for this form fall in the range of several days. The version without the linker is cleared in minutes, with estimates often near thirty minutes in animal work. These figures come from small studies and vary with assay method, species, and route, so they are best read as approximate rather than fixed constants.
==== Stress management ==== Although psychological stress is recognized as a risk factor for type 2 diabetes, the effect of stress management interventions on disease progression are not established. A Cochrane review is under way to assess the effects of mindfulness‐based interventions for adults with type 2 diabetes.
=== Female pubertal development === Estrogens are responsible for the development of female secondary sexual characteristics during puberty, including breast development, widening of the hips, and female fat distribution. Conversely, androgens are responsible for pubic and body hair growth, as well as acne and axillary odor.
=== Stability of proteins from rates of oxidation (SPROX) === Stability of Proteins from Rates of Oxidation also rests upon the assumption that ligand binding confers protection to proteins from manners of degradation, this time from oxidation of methionine residues. In SPROX, a lysate is split and treated with drug or a DMSO control, then each group is further aliquoted into separate samples with increasing concentrations of the chaotrope and denaturant guanidinium hydrochloride (GuHCl). Depending on the concentration of GuHCl, proteins will unfold to varying degrees. Each sample is then reacted with hydrogen peroxide, which oxidizes methionine residues. Proteins that are stabilized by the drug will remain folded at higher concentrations of GuHCl and will experience less methionine oxidation. Oxidized methionine residues can be quantified via LC-MS/MS and used to generate methionine stability curves, which are a proxy for drug binding. There are drawbacks to the SPROX assay, namely that the only relevant peptides from SPROX samples are those with methionine residues, which account for approximately one-third of peptides, and for which there are currently no viable enrichment techniques. Only those methionines that are exposed to oxidation provide meaningful information, and not all differences in methionine oxidation are consistent with protein stabilization. Without enrichment, LC-MS/MS analysis of these peptides is challenging, as the contribution of other sample components to mass spectrometer noise can drown out relevant signal.
== In physics == Usually the time-of-flight tube used in mass spectrometry is praised for simplicity, but for precision measurements of charged low energy particles the electric and the magnetic field in the tube has to be controlled within 10 mV and 1 nT respectively. The work function homogeneity of the tube can be controlled by a Kelvin probe. The magnetic field can be measured by a fluxgate compass. High frequencies are passively shielded and damped by radar absorbent material. To generate arbitrary low frequencies field the screen is parted into plates (overlapping and connected by capacitors) with bias voltage on each plate and a bias current on coil behind plate whose flux is closed by an outer core. In this way the tube can be configured to act as a weak achromatic quadrupole lens with an aperture with a grid and a delay line detector in the diffraction plane to do angle resolved measurements. Changing the field the angle of the field of view can be changed and a deflecting bias can be superimposed to scan through all angles. When no delay line detector is used focusing the ions onto a detector can be accomplished through the use of two or three einzel lenses placed in the vacuum tube located between the ion source and the detector. The sample should be immersed into the tube with holes and apertures for and against stray light to do magnetic experiments and to control the electrons from their start.
Sources: en.wikipedia.org
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== Clinical significance == Increased and supraphysiological ER stress in pancreatic β cells disrupts normal insulin secretion, leading to hyperinsulinemia and consequently peripheral insulin resistance associated with obesity in humans. Human clinical trials also suggested a causal link between obesity-induced increase in insulin secretion and peripheral insulin resistance. Abnormalities in XBP1 lead to a heightened endoplasmic reticulum stress response and subsequently causes a higher susceptibility for inflammatory processes that may even contribute to Alzheimer's disease. In the colon, XBP1 anomalies have been linked to the inflammatory bowel diseases including Crohn's disease. The unfolded protein response (UPR) is a cellular stress response related to the endoplasmic reticulum. The UPR is activated in response to an accumulation of unfolded or misfolded proteins in the lumen of the endoplasmic reticulum. The UPR functions to restore normal function of the cell by halting protein translation, degrading misfolded proteins, and activating the signaling pathways that lead to increasing the production of molecular chaperones involved in protein folding. Sustained overactivation of the UPR has been implicated in prion diseases as well as several other neurodegenerative diseases and the inhibition of the UPR could become a treatment for those diseases.
The reaction happens with two metal cofactors (Mg or Mn) coordinated to the two aspartate residues on C1. They perform a nucleophilic attack of the 3'-OH group of the ribose on the α-phosphoryl group of ATP. The two lysine and aspartate residues on C2 selects ATP over GTP for the substrate, so that the enzyme is not a guanylyl cyclase. A pair of arginine and asparagine residues on C2 stabilizes the transition state. In many proteins, these residues are nevertheless mutated while retaining the adenylyl cyclase activity. There are ten known isoforms of adenylyl cyclases in mammals: These are also sometimes called simply AC1, AC2, etc., and, somewhat confusingly, sometimes Roman numerals are used for these isoforms that all belong to the overall AC class III. They differ mainly in how they are regulated, and are differentially expressed in various tissues throughout mammalian development.
Upregulation of receptors is the increase in receptor number or sensitivity of receptors. The receptors involved in functional antagonism are regulated in sensitivity, number and location. Therefore, changes in receptors are common. Using a long-term antagonist drug or continuous exposure to an antagonist may cause the upregulation and hypersensitivity of receptors, which means an increase in the number and sensitivity of receptors. The increase in the number of receptors is due to the increased expression of receptors after prolonged inhibition. The upregulation of receptors is important in the clinical aspect. One example of upregulation of receptors is the upregulation of β-receptors caused by β receptor antagonists (also called β-blocker). The prolonged use of β-blockers results in the blockade of β-receptors, causing cells (mainly myocardial cells) to increase their expression of β-receptor. After removing the blockage, more receptors available for stimulation, resulting in higher sensitivity of β-receptors called the hypersensitivity of β-receptors. Abrupt discontinuation of β-blocker may potentially aggravate coronary artery disease, tachycardia, or even sudden cardiac death. Therefore, to prevent the adverse effects, doses of β-blocker must be reduced gradually over 10–14 days.
Sources: en.wikipedia.org
No. It is a synthetic analogue modeled on the first 29 residues of human GHRH. The substitutions and any linker are laboratory modifications rather than features of the endogenous peptide.
Early development used the albumin-binding form, and a shorter variant was later discussed under the same label. Because the two differ in half-life and handling, ambiguity arises whenever a source omits the variant designation.
The compound derives from that fragment but is not identical to it. The parent fragment lacks the stabilizing substitutions, so its degradation rate and duration of action differ noticeably.
It acts on the growth hormone-releasing hormone receptor found on pituitary somatotroph cells. Activation of that receptor triggers growth hormone release through a cyclic AMP dependent pathway.