Everything below concerns somatotroph. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-04-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
CJC-1295 belongs to a family of synthetic peptides modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound is built from the first twenty-nine amino acids of the natural human sequence, a fragment that retains full receptor binding capacity. Native growth hormone-releasing hormone is degraded quickly in circulation, so the fragment alone has limited practical value. Early work therefore focused on chemical modifications that preserve receptor binding while slowing enzymatic breakdown. The result is a molecule described in the literature as a long-acting analog of the natural hormone.
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.
| Property | Value | Notes |
|---|---|---|
| Purity assessment | Reverse-phase HPLC | Reported as area percentage |
| Identity confirmation | Mass spectrometry | Electrospray or laser desorption |
| Powder storage | Minus 20 degrees Celsius or lower | Dark and dry conditions |
| Solution storage | Two to eight degrees Celsius | Avoid repeated freeze-thaw |
| Appearance | White to off-white powder | Common lyophilized form |
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.
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.
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.
== Synthesis == Generally, synthesis of the characteristic scaffold of ebselen, the benzoisoselenazolone ring system, can be achieved either through reaction of primary amines (RNH2) with 2-(chloroseleno)benzoyl chloride (Route I), by ortho-lithiation of benzanilides followed by oxidative cyclization (Route II) mediated by cupric bromide (CuBr2), or through the efficient Cu-catalyzed selenation / heterocyclization of o-halobenzamides, a methodology developed by Kumar et al. (Route III).
Methyltestosterone is used in the treatment of delayed puberty, hypogonadism, cryptorchidism, and erectile dysfunction in males, and in low doses to treat menopausal symptoms (specifically for osteoporosis, hot flashes, and to increase libido and energy), postpartum breast pain and engorgement, and breast cancer in women. Growth hormones used in veterinary medicine (e.g. trenbolone acetate) are also used in intensive animal farming for faster gains in muscle mass for higher yields of meat from livestock and higher milk production in the dairy industry.
== Medicinal Chemistry career == While at Merck & Co., where he was hired as a researcher in 1950, he led a team that developed a method to synthesize the enzyme ribonuclease. His team was successful, with their results announced in January 1969 parallel with those from a separate team led by Bernd Gutte and Robert Bruce Merrifield at Rockefeller University who also achieved synthesis of the same enzyme using a different method. The comparatively simple 124-amino acid structure of ribonuclease made it a logical target for the first enzyme to synthesize. Hirschmann's team built the enzyme in amino acid groups from six to 17 in length which were assembled into two large sections that were linked together, while Merrifield's approach was to assemble the entire enzyme by linking one amino acid at a time at the end of a chain. The achievement was front-page news in The New York Times, heralding the fact that "An Enzyme Is Synthesized for First Time" and providing coverage of a joint announcement by the two teams. While no immediate applications were foreseen, the Merck team noted that the ability to synthesize enzymes opened a new class of drugs for potential therapeutic use. In Hirschmann's obituary in The New York Times, chemist Daniel Rich described the feat of synthesizing an enzyme as "a huge discovery" that "bridged the interface between chemistry and biology", and that by the time of Hirschmann's death the accomplishment was "just routine".
Water Proteins Fats (or lipids) Hydroxyapatite in bones Carbohydrates such as glycogen and glucose DNA and RNA Inorganic ions such as sodium, potassium, chloride, bicarbonate, phosphate Gases mainly being oxygen, carbon dioxide Many cofactors. The estimated contents of a typical 20-micrometre human cell is as follows:
Sources: en.wikipedia.org
{\displaystyle {\begin{cases}{\ce {^{244}_{96}Cm ->[{\ce {(\alpha,n)}}] ^{247}_{98}Cf ->[\epsilon][3.11 \ {\ce {h}}] ^{247}_{97}Bk}}\\{\ce {^{244}_{96}Cm ->[{\ce {(\alpha,p)}}] ^{247}_{97}Bk}}\end{cases}}}
Among the most famous were Milon of Croton, who won six wrestling events in six consecutive Olympics, along with seven events in the Pythian Games, nine events in the Nemean Games and ten events in the Isthmian Games and also Astylos of Croton, who won six running events in three consecutive Olympics. Through Alcmaeon of Croton (a philosopher and medical theorist) and Pythagoras (a mathematician and philosopher), who moved to Kroton in 530 BCE, the city became a center of philosophy, science and medicine. The Greeks of Sybaris created "Intellectual Property". The Sybarites founded at least 20 other cities, including Poseidonia (Paestum in Latin, on the Tyrrhenian coast of Lucania), Laüs (on the border with Lucania) and Scidrus (on the Lucanian coast in the Gulf of Taranto). Locri was renowned as the town where Zaleucus created the first Western Greek law, the "Locrian Code" and the birthplace of ancient epigrammist and poet Nossis. The Greek cities of Calabria came under pressure from the Lucanians who conquered the north of Calabria and pushed further south, taking over part of the interior, probably after they defeated the Thurians near Laus in 390 BCE. Decades later the Bruttii took advantage of the weakened Greek cites caused by wars between them and took over Hipponium, Terina and Thurii. The Bruttii helped the Lucanians fight Alexander of Epirus (334–32 BCE), who had come to the aid of Tarentum (in Apulia), which was also pressured by the Lucanians.
=== Russian reaction === Russia welcomed Trump's tariffs against its NATO allies, with Kremlin officials saying it was evidence that the transatlantic alliance was collapsing. The Russian government newspaper Rossiyskaya Gazeta praised Trump's push to take over Greenland and welcomed the strain it was causing between the US and Europe.
Sources: en.wikipedia.org
The powder is normally held at minus twenty degrees Celsius or below. Light and moisture exposure should be minimized. Repeated warming and cooling cycles are avoided.
Reverse-phase high-performance liquid chromatography is used for purity. Mass spectrometry confirms molecular weight and sequence integrity. Amino acid analysis offers an additional compositional check.
Published stability data for dissolved material are limited and vary with conditions. Refrigerated solutions are generally used within a short period. The exact shelf life depends on concentration, buffer, and handling.
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.