drug affinity complex raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-01-21 and is reviewed periodically as new material appears.
The peptide binds GHRH receptors on somatotroph cells within the anterior pituitary, triggering a signalling cascade that increases growth hormone secretion. Its improved resistance to dipeptidyl peptidase IV degradation distinguishes it from the parent hormone. In the DAC-bearing version, a maleimide group reacts with a cysteine residue on serum albumin, forming a covalent bond that keeps the peptide in circulation far longer. That albumin attachment is the central design feature separating the two research variants.
Pharmacokinetic behaviour differs sharply between the two forms. The DAC-bearing peptide shows an extended circulation time measured in days, whereas the version without the complex is cleared within roughly half an hour. This gap shapes how researchers design dosing schedules in animal models. Whether the prolonged presence of the DAC form produces effects meaningfully different from the short-acting variant remains an open question, since comparative human data are scarce.
CJC-1295 is a synthetic peptide designed to mimic growth hormone-releasing hormone (GHRH), the endogenous signal that prompts the pituitary gland to release growth hormone. The compound is a modified fragment of the natural hormone, spanning the first twenty-nine amino acids of GHRH with several substitutions that slow enzymatic breakdown. Two variants circulate in research settings: one carrying a drug affinity complex (DAC) and one without it. The DAC-free form is frequently labelled Mod GRF(1-29) in catalogs and discussion forums.
CJC-1295 is the name used for a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound was described by a Canadian drug discovery company in the mid-2000s as a long-acting research tool. Two closely related molecules share the name in practice: one carries a drug affinity complex, or DAC, group, and one does not. The distinction matters because the two behave differently in circulation.
The peptide backbone corresponds to GRF(1-29), the first 29 residues of native growth hormone-releasing hormone, which retains most of the receptor-activating activity of the full-length molecule. Four substitutions distinguish the analog from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes slow cleavage by dipeptidyl peptidase IV, the enzyme that degrades native hormone in plasma within minutes. The outcome is improved enzymatic stability combined with a still brief residence time when no additional modification is present.
Naming in this area is inconsistent, and readers should treat product labels with care. In much of the literature and in vendor catalogs, the unqualified term refers to the albumin-binding version, while the version lacking the DAC group appears as modified GRF(1-29), mod GRF(1-29), or the same name with a without-DAC qualifier. Because one abbreviation has been applied to both materials, the only reliable way to identify a sample is to check the stated sequence and the presence of the linker.
| Property | Value | Notes |
|---|---|---|
| Molecular weight (with DAC) | ~3647 Da | Calculated from the full amino acid sequence |
| Molecular weight (without DAC) | ~3368 Da | Mod GRF(1-29) variant |
| Appearance | White lyophilized powder | Typical form supplied for research |
| Solubility | Soluble in water | Dissolves in aqueous buffers |
| Receptor target | GHRH receptor | Expressed on pituitary somatotroph cells |
Two related peptides circulate under the CJC-1295 label, and they differ mainly in how long they persist in circulation. The version carrying a drug affinity complex includes a maleimidopropionic acid linker that forms a covalent bond with serum albumin. The other version, usually written as modified GRF(1-29) or tetrasubstituted GRF(1-29), lacks that linker and is cleared quickly. Mixing the two produces inconsistent readings of published half-life values, because the linker rather than the receptor-facing sequence drives most of the difference.
The core sequence keeps the receptor-binding region of GHRH while replacing four positions that are vulnerable to dipeptidyl peptidase-4 and other proteases. Substitutions at positions 2, 8, 15, and 27 raise metabolic stability relative to the natural hormone. The N-terminal residues remain essential for activity, so changes there generally lower potency. Molecular weight sits near 3368 daltons for the tetrasubstituted analog without the linker, while the albumin-binding form is heavier because of the added maleimide group.
CJC-1295 is a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. Its sequence corresponds to the first twenty-nine residues of human GHRH, with four substitutions that slow enzymatic breakdown. Early descriptions placed the compound in research on growth hormone deficiency and related conditions, and later literature groups it with the long-acting GHRH analogs. The name appears in both laboratory and popular fitness writing, where it sometimes labels chemically different peptides.
Characterization of this peptide relies on a small set of routine techniques. Reversed-phase high-performance liquid chromatography separates the target from truncated or oxidized by-products and yields a purity estimate when paired with ultraviolet detection near 214 nanometers. Mass spectrometry, either electrospray coupled to liquid chromatography or matrix-assisted laser desorption, confirms that the observed mass matches the value calculated for the expected sequence. Amino acid analysis, and enzymatic digestion followed by fragment mapping, are used when the sequence itself rather than the mass requires verification.
Stability depends heavily on physical state. A lyophilized powder kept dry, desiccated, and shielded from light typically holds its integrity for months to years at minus twenty degrees Celsius, and longer at minus eighty. Once dissolved, the peptide becomes far more vulnerable, since peptide bond hydrolysis, oxidation of susceptible residues, and aggregation all proceed faster in solution. Buffers near neutral pH are generally gentler than strongly acidic or alkaline conditions. Repeated freeze-thaw cycles and exposure to air-liquid interfaces during vigorous mixing cause losses that are easy to overlook.
Verification matters because research peptides vary widely in quality. A certificate of analysis is only as reliable as the method behind it, and a single chromatographic trace reveals little about counter-ions, residual solvents, or water content. Independent laboratories commonly pair mass confirmation with chromatographic purity and, where relevant, quantify water along with acetate or trifluoroacetate content. Reported purity figures are not standardized across suppliers, so a stated value such as ninety-eight percent is not directly comparable unless the analytical method, column, and detection wavelength accompany it.
The compound emerged from work at a Canadian biotechnology firm in the early 2000s. Early human studies examined its effect on growth hormone and insulin-like growth factor 1 in healthy volunteers and in people with HIV-associated fat redistribution. Reports described sustained increases in both markers after a single injection. Development did not advance to regulatory approval, and the clinical programme was later discontinued. The molecule is now encountered mainly as a research chemical rather than a marketed medicine.
Two forms circulate in research settings and are frequently confused. One carries the drug affinity complex and is often written as CJC-1295 with DAC; the other lacks that group and is usually called modified GRF(1-29). The two share the same core sequence but differ sharply in how long they persist in blood. Products labelled only as CJC-1295 normally refer to the version carrying the complex. Documentation that omits the distinction leaves the intended molecule ambiguous.
CJC-1295 is a synthetic peptide built as a long-acting analogue of growth hormone-releasing hormone. Its backbone matches the first twenty-nine residues of the natural human hormone, with four amino acid substitutions added to slow enzymatic breakdown. A reactive maleimide group, commonly termed the drug affinity complex, allows the peptide to attach to circulating albumin after administration. That albumin attachment keeps the molecule in the bloodstream for an extended period instead of being cleared within minutes.
=== Toxicokinetics === Inhaling cadmium-laden dust quickly leads to respiratory tract and kidney problems which can be fatal (often from kidney failure). Ingestion of any significant amount of cadmium causes immediate poisoning and damage to the liver and the kidneys. Compounds containing cadmium are also carcinogenic.
In the molecule lawrencium dihydride (LrH2), which is predicted to be bent, the 6d orbital of lawrencium is not expected to play a role in the bonding, unlike that of lanthanum dihydride (LaH2). LaH2 has La–H bond distances of 2.158 Å, while LrH2 should have shorter Lr–H bond distances of 2.042 Å due to the relativistic contraction and stabilization of the 7s and 7p orbitals involved in the bonding, in contrast to the core-like 5f subshell and the mostly uninvolved 6d subshell. In general, molecular LrH2 and LrH are expected to resemble the corresponding thallium species (thallium having a 6s26p1 valence configuration in the gas phase, like lawrencium's 7s27p1) more than the corresponding lanthanide species. The electron configurations of Lr+ and Lr2+ are expected to be 7s2 and 7s1 respectively. However, in species where all three valence electrons of lawrencium are ionized to give at least formally the Lr3+ cation, lawrencium is expected to behave like a typical actinide and the heavier congener of lutetium, especially because the first three ionization potentials of lawrencium are predicted to be similar to those of lutetium. Hence, unlike thallium but like lutetium, lawrencium would prefer to form LrH3 than LrH, and LrCO is expected to be similar to the also unknown LuCO, both metals having valence configuration σ2π1 in their monocarbonyls. The pπ–dπ bond is expected to be seen in LrCl3 just as it is for LuCl3 and more generally all the LnCl3.
== Evidence == It has been demonstrated in animal experiments that there is an improvement in sorbitol levels and Na+/K+ ATPase activity leading to improved nerve conduction velocity. Diabetic rats treated with epalrestat showed improvement in morphological abnormalities of nerves. In a placebo controlled double blind trial of 196 patients, it was shown that Epalrestat in a dose of 150 mg/day improved the effects of diabetic neuropathy like upper limb spontaneous pain, motor nerve conduction velocity, thresholds of vibratory sensation and autonomic nerve function as compared to a placebo. These effects were significantly better in those with poorer control of diabetes. A systematic review and metaanalysis showed that based on the results of 10 articles, it can be concluded that Epalrestat has some benefit in the control of diabetic cardiovascular autonomic neuropathy but only in the early or mild cases. It also doesn't influence glycaemic control.
Sources: en.wikipedia.org
=== Laboratory synthesis === As early as the 1860s, experiments demonstrated that biologically relevant molecules can be produced from interaction of simple carbon sources with abundant inorganic catalysts. The spontaneous formation of complex polymers from abiotically generated monomers under the conditions posited by the "soup" theory is not straightforward. Besides the necessary basic organic monomers, compounds that would have prohibited the formation of polymers were also formed in high concentration during the Miller–Urey experiment and Joan Oró experiments. Biology uses essentially 20 amino acids for its coded protein enzymes, representing a very small subset of the structurally possible products. Since life tends to use whatever is available, an explanation is needed for why the set used is so small. Formamide is attractive as a medium that potentially provided a source of amino acid derivatives from simple aldehyde and nitrile feedstocks.
=== Tissue distribution === Elastin serves an important function in arteries as a medium for pressure wave propagation to help blood flow and is particularly abundant in large elastic blood vessels such as the aorta. Elastin is also very important in the lungs, elastic ligaments, elastic cartilage, the skin, and the bladder. It is present in jawed vertebrates.
==== Infections ==== Some observational studies have detected significant associations between benzodiazepines and respiratory infections such as pneumonia where others have not. A large meta-analysis of pre-marketing randomized controlled trials on the pharmacologically related Z-Drugs suggest a small increase in infection risk as well. An immunodeficiency effect from the action of benzodiazepines on GABA-A receptors has been postulated from animal studies.
Transcription is the process by which genetic information stored in DNA is copied into RNA by the enzyme RNA polymerase. During transcription, RNA polymerase binds to a promoter sequence on the DNA and synthesizes a complementary RNA strand (mRNA) from the DNA template. This process differs between prokaryotes and eukaryotes. In prokaryotes, transcription occurs in the cytoplasm. Because prokaryotes lack a membrane-bound nucleus, ribosomes can attach to the nascent mRNA strand and begin translation while transcription is still in progress. In eukaryotes, transcription occurs within the cell nucleus. The initial product of transcription is not functional mRNA but is termed precursor mRNA or pre-mRNA. This pre-mRNA must undergo extensive processing (including 5' capping, splicing to remove non-coding introns, and 3' polyadenylation) to become mature mRNA. Once processed, the mature mRNA is exported from the nucleus to the cytoplasm for translation.
Sources: en.wikipedia.org
The synthetic peptide keeps the receptor-binding region of GHRH but carries substitutions that resist enzymatic cleavage. In the DAC version, an added group also anchors the molecule to albumin, extending its presence in the bloodstream.
The maleimide group forms a covalent link with albumin, an abundant blood protein. This attachment slows clearance, so a single administration persists much longer than the unmodified peptide. The feature is the main reason the two variants are handled differently in study design.
It is not an approved therapeutic product in major regulatory jurisdictions. It appears in research chemical catalogs and scientific literature rather than pharmacy shelves. Clinical development was limited and did not reach approval.
No. It is a laboratory-made analog of growth hormone-releasing hormone. The natural hormone is a 44-residue peptide, while the analog is built on a shorter 29-residue fragment.