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Background And Molecular Design — Deep Dive

By Editorial Desk · published 2026-02-02 · last reviewed 2026-03-09 · Blog

GHRH analog raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.

Reviewed 2026-03-09. Anything still debated is marked as such rather than presented as settled.

Background and Molecular Design

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.

Background and Molecular Features

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.

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.

Cjc-1295 at a glance

PropertyValueNotes
ClassSynthetic peptideGHRH receptor agonist
Sequence length29 amino acidsDerived from human GHRH
Molecular weightAbout 3368 Da without linkerAlbumin-binding form is heavier
AppearanceWhite to off-white lyophilized powderCommon form for research reference material
Typical storage-20 °C or below, desiccatedProtect powder from light and moisture

Molecular Background and Naming

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.

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Handling Storage And Analytical Methods

Reconstitution is typically performed with sterile water or bacteriostatic water, added slowly against the vial wall. The resulting solution should be clear and colorless; cloudiness or visible particles suggest a problem with the material or the diluent. Once in solution, the peptide is less stable than the dry powder. Refrigerated storage at two to eight degrees Celsius is common for short-term holding, while freezing aliquots is described for longer periods.

Purity is most often assessed by reversed-phase high-performance liquid chromatography, reported as a percentage of total peak area. Identity is confirmed by mass spectrometry, which yields a molecular ion consistent with the expected sequence. Amino acid analysis and peptide mapping provide additional characterization. Reported purity values are method-dependent, so figures from different laboratories are not always directly comparable without details of column, gradient, and detection wavelength.

Handling, Stability and Analysis

Lyophilised powder is the usual supplied form. The material is hygroscopic, so vials are typically equilibrated to room temperature before opening in order to prevent condensation on the contents. Long-term storage is generally described at minus twenty degrees Celsius or colder, protected from light and moisture. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of soluble material. A reconstituted solution is considerably less stable than the dry powder and is normally kept refrigerated for short periods only.

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.

Handling Storage and Quality Control

Lyophilized material is typically stored at minus twenty degrees Celsius or lower. Keeping the vial dry and protected from light preserves peptide integrity. Repeated freeze-thaw cycles can cause aggregation or loss of activity. Once dissolved, solutions are generally kept at two to eight degrees Celsius. Stability data for reconstituted solutions vary, and long-term behavior is not fully established. Working aliquots reduce the number of times a stock container is opened.

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.

Reference notes

=== Vitamin B12-dependent enzymes === The cobalt-containing Vitamin B12 (also known as cobalamin) catalyzes the transfer of methyl (−CH3) groups between two molecules, which involves the breaking of C−C bonds, a process that is energetically expensive in organic reactions. The metal ion lowers the activation energy for the process by forming a transient Co−CH3 bond. The structure of the coenzyme was famously determined by Dorothy Hodgkin and co-workers, for which she received a Nobel Prize in Chemistry. It consists of a cobalt(II) ion coordinated to four nitrogen atoms of a corrin ring and a fifth nitrogen atom from an imidazole group. In the resting state there is a Co−C sigma bond with the 5′ carbon atom of adenosine. This is a naturally occurring organometallic compound, which explains its function in trans-methylation reactions, such as the reaction carried out by methionine synthase.

== History == The establishment of the National Legislature is one of the new institutions created upon the independence of South Sudan in 2011. In substance, it is also a successor to the Southern Sudan Legislative Assembly, itself established in 2005 by the Constitution of Southern Sudan. General elections are scheduled to be held in 2026.

On the other hand, hybrids of tomato and diploid potato can be created in the lab by somatic fusion, and are partially fertile, providing evidence of the close relationship between these species. Newer genomic studies have found that the tomato and the potato are very close relatives, forming a tight clade within Solanum. A 2025 study suggests that the potato lineage may have been created by hybridization of a plant from the tomato lineage (not necessarily the modern tomato species) with a plant from the S. etuberosum lineage.

Sources: en.wikipedia.org

Reference notes

=== Cardiovascular safety === The cardiovascular safety profile of dapoxetine has been studied extensively during the drug development. Phase I trials showed that dapoxetine had neither clinically significant electrocardiographic effects nor delayed repolarization effects, with dosing up to four-fold greater than the maximum recommended dosage, which is 60 mg. Phase III studies in men with PE showed a safety and well tolerated profile of dapoxetine with dosing of 30 and 60 mg. No cardiovascular adverse had been found.

=== 1969 === January 20: Richard Nixon becomes President of the United States. March 2: Border clashes between the Soviet Union and China. March 17: the U.S. begins bombing Communist sanctuaries in Cambodia. July 16: Apollo 11 is launched. July 20: the U.S. accomplishes the first crewed Moon landing, Apollo 11. Crewed by Neil Armstrong, "Buzz" Aldrin, and Michael Collins. July 24: Apollo 11 returns to Earth. July 25: "Vietnamization" begins with U.S. troop withdrawals from Vietnam and the burden of combat being placed on the South Vietnamese. September 1: Muammar Gaddafi overthrows the Libyan monarchy and expels British and American personnel. Libya aligns itself with the Soviet Union. September 2: North Vietnamese leader Ho Chi Minh dies. October 21: Siad Barre overthrows the government of Somalia in a bloodless coup. He declares himself President of Somalia and reorganizes the country into a one-party communist state; the Somali Democratic Republic. November 17: The Strategic Arms Limitation Talks begin in Helsinki. November 27–December 6: the al-Wadiah War was fought between South Yemen and Saudi Arabia. December 12: A bomb planted by far-right extremists sets off in a bank in Milan, Italy, killing 17 people and injuring 88. This event (remembered as the Piazza Fontana bombing) is one of the bloodiest terrorist attacks Italy would receive during the years of lead.

== Resurgence == By the late 2010s, many observers, including The New York Times, pointed to Detroit's economic and cultural resurgence. This resurgence was primarily due to private and public investment revitalizing the city's social and economic dynamics. Detroit has achieved a renewed sense of interest through reinvestment and revamped social policies. It serves as a model for other areas to learn how to re-energize their urban centers. In 2024, the United States Census Bureau reported that Detroit experienced a slight population increase in its 2023 estimates, marking the city's first recorded growth since 1957. Evidence of Detroit's resurgence is most readily found in the Midtown Area and the Central Business District, which have attracted a number of high-profile investors. Most notably, Dan Gilbert has heavily invested in the acquisition and revitalization of a number of historic buildings in the Downtown area. A primary focus of private real estate investment has been to position Detroit's Central Business District as an attractive site for the investment of technology companies such as Amazon, Google, and Microsoft. Approaches to the private investment of Midtown, however, have prioritized re-establishing Midtown as the cultural and commercial center of the city. Midtown Cultural Connection's DIA Plaza Project, for instance, aims to unify the city's cultural district—which includes the Detroit Institute of Arts, Detroit Public Library, the Charles H.

Sources: en.wikipedia.org

Frequently asked questions

What is the difference between CJC-1295 and natural GHRH?

Natural GHRH is degraded quickly by dipeptidyl peptidase-4 and related enzymes, giving it a half-life measured in minutes. CJC-1295 carries substitutions that slow that breakdown, so it stays intact longer. Both act at the same pituitary receptor and produce the same class of signal.

Why does one name cover two different peptides?

The label was first attached to the albumin-binding form during early development work. A shorter analog without the linker later became known by the same name in informal use. Published papers normally state which version was studied, so the methods section resolves the ambiguity.

Is CJC-1295 a steroid or a natural hormone?

It is a synthetic peptide rather than a steroid, and it does not occur naturally in the body. Its sequence is derived from a hypothalamic hormone called growth hormone-releasing hormone. It works as a receptor agonist rather than as a replacement for that hormone.

Is CJC-1295 a natural hormone?

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.

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