The short version of GHRH receptor fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-03-06. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | GHRH analog, not a steroid |
| Backbone length | 29 amino acids | Based on GRF(1-29) |
| Substitutions | Four positions | D-Ala2, Gln8, Ala15, Leu27 |
| Appearance | White to off-white powder | Typical lyophilized research material |
| Common synonyms | Modified GRF(1-29) | Usage varies between sources |
Reverse-phase high-performance liquid chromatography is the standard tool for purity assessment. The technique separates the target peptide from truncated or modified byproducts. Mass spectrometry confirms molecular weight and supports sequence verification. Electrospray ionization and matrix-assisted laser desorption are both used. Amino acid analysis provides an independent check on composition. Purity values are commonly reported as area percentage from the chromatogram. Residual trifluoroacetate and water content are also measured in many quality programs.
Batch-to-batch consistency depends on solid-phase peptide synthesis and subsequent purification. Coupling efficiency, resin choice, and cleavage conditions all affect the final profile. Counter-ion content and moisture can shift the apparent mass of a batch. Documentation typically includes a certificate of analysis with chromatograms and spectra. Independent verification by a second laboratory is sometimes requested. Whether a given certificate reflects the actual vial contents depends on chain of custody. Analytical methods themselves carry uncertainty that should be stated alongside results.
Two forms circulate under the CJC-1295 name, and they differ by a single appended group. The version without a drug affinity complex carries four substitutions along the peptide chain, including a D-alanine near the amino terminus and replacements at three other positions. These changes block the enzyme dipeptidyl peptidase IV and remove a methionine residue that is prone to oxidation. The modified fragment is frequently labeled MOD GRF 1-29. Naming conventions are inconsistent across informal sources, which is a common source of confusion.
The second form adds a maleimide-bearing linker to the lysine at the carboxyl end. This group reacts with cysteine-34 on circulating serum albumin, forming a covalent bond that keeps the peptide in the bloodstream for far longer. ConjuChem developed the molecule as a way to extend the action of a peptide without frequent administration. The albumin attachment is the defining structural feature of the drug affinity complex version. Whether continuous exposure produces effects distinct from shorter pulses remains an unresolved research question.
=== Contributions to mechanical properties of biomaterials === Natural materials show a combination of normally contradicting mechanical properties (softness and toughness), due to their hierarchical structures of fibrils across multiple length scales. These fibrils are often oriented in a single direction, leading to anisotropic mechanical response in the resulting biocomposite material. This is a prime advantage as most of these materials withstand stresses in a single direction, and so a higher yield and fracture stress in the direction of the applied stress ensures the material structural integrity. Macro, micro, and nano fibrils enable the material to resist fracture through a series of fracture resistance mechanisms:
==== Chitin ==== Chitin, a polymer of N-acetyl glucosamine, is not produced by mammals but is used extensively by various groups of invertebrates. It is an essential part of the shell of mulloscs, the cuticle of arthropods, the fibrous ECM of sponges, and the squid beak. Chitin forms into fibers and the fibers are organized into one of three crystalline shapes, α/β/γ. The chitin in arthropods and sponges are mostly in the α shape, organized into sheets (laminae) with the help of β-sheet-rich chitin-binding proteins. The chitin in squid beak is in the β form, organized into a hard composite material with protein coacervates. The cocoon contains γ-chitin. Chitin also makes up the cell wall of fungi. The stomachs of mammals (including humans) produce chitinase (acidic mammalian chitinase, AMCase), allowing them to break down chitin found in the diet. Despite being digestible, chitin also acts as a dietary fiber in mammals. The production of AMCase requries an immune response to be mounted against chitin.
Type II collagen is the basis for hyaline cartilage, including the articular cartilages at joint surfaces. It is formed by homotrimers of collagen, type II, alpha 1 chains. It makes up 50% of all protein in cartilage and 85–90% of collagen of articular cartilage. Type II collagen is organised into fibrils. This fibrillar network of collagen allows the cartilage to entrap the proteoglycan aggregate, as well as providing tensile strength to the tissue. Oral administration of native type II collagen induces oral tolerance to pathological immune responses and the administration of type II collagen tablets together with paracetamol might be more effective at reducing symptoms of osteoarthritis than paracetamol by itself.
Sources: en.wikipedia.org
=== Extraction === Extraction is performed with either water or acid solutions at appropriate temperatures. All industrial processes are based on neutral or acid pH values because although alkali treatments speed up conversion, they also promote degradation processes. Acidic extraction conditions are extensively used in the industry, but the degree of acid varies with different processes. This extraction step is a multistage process, and the extraction temperature usually is increased in later extraction steps, which ensures minimum thermal degradation of the extracted gelatin.
==== Topical preparations ==== Cosmetics may contain a non-gelling variant of gelatin under the name hydrolyzed collagen (hydrolysate). Hydrolyzed collagen may be found in topical (applied to the skin) creams, acting as a product texture conditioner, and moisturizer.
== Structure == A tendon is made of dense regular connective tissue, whose main cellular components are special fibroblasts called tendon cells (tenocytes). Tendon cells synthesize the tendon's extracellular matrix, which abounds with densely-packed collagen fibers. The collagen fibers run parallel to each other and are grouped into fascicles. Each fascicle is bound by an endotendineum, which is a delicate loose connective tissue containing thin collagen fibrils and elastic fibers. A set of fascicles is bound by an epitenon, which is a sheath of dense irregular connective tissue. The whole tendon is enclosed by a fascia. The space between the fascia and the tendon tissue is filled with the paratenon, a fatty loose connective tissue. Normal healthy tendons are anchored to bone by Sharpey's fibres.
(Cm, Z=96): Curium-247, 1.64 × 107 years / 1.56 × 107 years (Am, Z=95): Americium-243; 7,370 years (Bk, Z=97): Berkelium-247; 1.4 × 103 years / 1380 years (Cf, Z=98): Californium-251; 898 years (Es, Z=99): Einsteinium-252; 471.7 days (Fm, Z=100): Fermium-257; 100.5 days (Md, Z=101): Mendelevium-258; 51.5 days (Lr, Z=103): Lawrencium-262; 3.6 hours = 216 minutes (No, Z=102): Nobelium-259; 58 minutes (Rf, Z=104): Rutherfordium-263; approximately 10 minutes (Sg, Z=106): Seaborgium-269; 5 ± 2 minutes (Bh, Z=107): Bohrium-270; approximately 61 seconds
Sources: en.wikipedia.org
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.
The original material included a linker that binds serum albumin. A later variant removed that linker to reduce the duration of action. Catalogs and papers did not consistently adopt separate names, so both remain widely labeled with the same term.
The amino acid sequence and the presence or absence of the linker group. Mass measured by spectrometry gives an independent check that separates the two forms.
It binds the growth hormone-releasing hormone receptor on pituitary somatotroph cells. Receptor activation raises cyclic AMP and promotes release of stored growth hormone granules. Because the peptide persists longer than natural releasing hormone, stimulation is prolonged rather than brief.