If you have been reading about Reversed-phase HPLC and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-07-31. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Class | Synthetic peptide | GHRH receptor agonist |
| Sequence length | 29 amino acids | Derived from human GHRH |
| Molecular weight | About 3368 Da without linker | Albumin-binding form is heavier |
| Appearance | White to off-white lyophilized powder | Common form for research reference material |
| Typical storage | -20 °C or below, desiccated | Protect powder from light and moisture |
Peptide degradation proceeds mainly through hydrolysis, oxidation of methionine, and deamidation of asparagine or glutamine residues. The maleimide group on the albumin-binding variant can also react with thiols or hydrolyze in aqueous media. Because these pathways accelerate with temperature and pH extremes, handling conditions strongly influence measured stability. Stability data in the public literature are limited and often generated under differing conditions, so general statements about shelf life should be read as approximate.
Research material is normally supplied as a freeze-dried powder in sealed vials. In that state the peptide is comparatively robust, but prolonged exposure to warmth, moisture, or light accelerates degradation. Storage at minus twenty degrees Celsius or lower, with desiccant and protection from light, is the commonly described practice. Vials should be allowed to reach room temperature before opening to limit condensation on the powder. Moisture uptake during handling is a recognized source of variability in later measurements.
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.
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.
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.
CJC-1295 is a synthetic analogue of growth hormone-releasing hormone, built on the 29-amino-acid GHRH(1-29) fragment. Four substitutions distinguish it from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes reduce enzymatic cleavage and extend the peptide's persistence in circulation. The compound is discussed in two forms, one carrying a drug affinity complex and one without it.
The drug affinity complex is a maleimidopropionic acid group attached to a lysine side chain. It reacts with the free thiol of cysteine-34 on circulating albumin, forming a covalent bond. This conjugation keeps the peptide in the bloodstream and shields it from rapid renal filtration and proteolysis. Reported circulation half-lives for the albumin-bound form fall in the range of roughly six to nine days in early human studies.
Binding to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and stimulates growth hormone synthesis and release. Because the peptide acts upstream of the pituitary, effects are mediated through endogenous growth hormone rather than direct receptor activation in peripheral tissues. Increases in insulin-like growth factor 1 are generally described as a downstream consequence. Most published human exposure data come from small early-stage studies, and the clinical significance of the pharmacokinetic profile remains incompletely characterized.
=== Recommendations === The IEEE standard 1188–1996 recommends replacing lithium-ion batteries in an electric vehicle, when their charge capacity drops to 80% of the nominal value. In what follows, we shall use the 20% capacity loss as a comparison point between different studies. We shall note, nevertheless, that the linear model of degradation (the constant % of charge loss per cycle or per calendar time) is not always applicable, and that a "knee point", observed as a change of the slope, and related to the change of the main degradation mechanism, is often observed.
=== Spring 1945 offensive in Italy === Kesselring's forces in Italy retained their formidable defensive positions in the northern Apennines in March 1945. The 6th Division rejoined the line in early April, shortly before the Allies launched their spring 1945 offensive, Operation Grapeshot. The units including Rhodesians took up positions opposite Monte Sole, Monte Abelle and Monte Caprara. The Rhodesian 25-pounder guns were posted slightly forward of their former positions, and B (Rhodesia) Squadron, Prince Alfred's Guard, moved to Grizzana. The Special Service Battalion provided armoured support to the 13th South African Motorised Brigade. The South Africans and Rhodesians launched a two-pronged assault on the German positions over the road to Bologna at 22:30 on 15 April 1945. The Cape Town Highlanders' advance up the steep cliffs of Monte Sole was obstructed by a German minefield that guarded the peak. The Rhodesian officer commanding the leading platoon, Second Lieutenant G B Mollett, took a section of men and dashed through the minefield to the summit; for this he later received the Distinguished Service Order. Hand-to-hand fighting on Monte Sole continued until dawn, when the Germans withdrew. The Witwatersrand Rifles meanwhile took Monte Caprara. The Cape Town Highlanders took Monte Abelle late on 16 April, advancing under heavy artillery fire to the summit before clearing it of Germans. The regiment lost 31 killed and 76 wounded during these actions, including three Rhodesians killed and three wounded.
== Treatment == The management of lipodermatosclerosis may include treating venous insufficiency with leg elevation and elastic compression stockings. In some difficult cases, the condition may be improved with the additional use of the fibrinolytic agent, stanozol. Fibrinolytic agents use an enzymatic action to help dissolve blood clots. Stanozol is injected directly into the affected area. Venous Ablation has also been known to help circulation in patients. Lifestyle changes such as maintaining a healthy weight & diet, exercising regularly, avoiding prolonged sitting or standing, and elevating your legs can play a significant role in managing lipodermatosclerosis and reducing its symptoms.
=== Synthesis === To synthesize dexamethasone, 16β-methylprednisolone acetate is dehydrated to the 9,11-dehydro derivative. This is then reacted with a source of hypobromite, such as basic N-bromosuccinimide, to form the 9α-bromo-11β-hydrin derivative, which is then ring-closed to an epoxide. A ring-opening reaction with hydrogen fluoride in tetrahydrofuran gives dexamethasone.
Sources: en.wikipedia.org
== History == The founding of the Jere Ngoni Kingdom was precipitated by the Mfecane, a period of widespread instability and state formation in Southern Africa, caused by pre-existing trends of political centralisation which were catalysed by the effects of international trade, environmental instability, and European colonial expansion. An early state was the Ndwandwe led by Zwide; after Zwide defeated Dingiswayo's Mthethwa c. 1816, the Mthethwa state disintegrated and some groups were incorporated into Ndwandwe. Zwide next engaged the expanding Zulu led by Shaka, but was defeated in battle c. 1819. Following this defeat, Zwangendaba (one of Ndwandwe's Indunas) led his group on a long-distance migration northwards, and they became known as the Jere Ngoni (separate from the Maseko Ngoni). Zwangendaba initially settled around the Mkomati River (north of Delagoa Bay), but fled north after clashing with other rulers such as Soshangane, Nxaba, and Mzilikazi. Zwangendaba entered onto the Zimbabwean Plateau and raided the Rozvi Empire for several years, before crossing the Zambezi in 1835. He left some troops behind with a relative of his (Nyamazana) who later killed the Rozvi king. In 1840 Zwangendaba's forces massacred many Tonga for allegedly causing him illness, and they captured many Chewa and Tumbuka. The Ngoni later reached the Ufipa Plateau, where in the late 1840s Zwangendaba died.
=== COVID-19 === NUVAXOVID is a recombinant subunit vaccine licensed for the prevention of SARS-CoV-2 infection. Market authorization was issued on 20 December 2021. The vaccine contains the SARS-CoV-2 spike protein produced using the baculovirus expression system, which is eventually adjuvanted with the Matrix M adjuvant.
Abortion access was a key topic during the campaign; it was on the ballot in up to 10 states in 2024, including the swing states of Arizona and Nevada. Abortion was a key issue for many voters in the 2022 elections. The issue continued to motivate voters in 2024 along with "the future of democracy in this country" and "high prices for gas, groceries and other goods." According to AP VoteCast, 25% of voters ranked abortion policy as the single most important factor in their vote, similar to the share who in 2022 said that the Supreme Court overturning Roe v. Wade was important to their vote. Of the states where abortion was on the ballot, measures seeking to expand or protect abortion access failed in Florida, South Dakota and Nebraska. Some pundits argued abortion rights referendums could help Harris in November. Democrats predominantly advocate for abortion access as a right, while Republicans generally favor significantly restricting the legality of abortion. Since becoming the presumptive nominee, Harris indicated her support for passing legislation which would restore the federal abortion right protections previously guaranteed by Roe. She argued Trump would let his anti-abortion allies implement Project 2025 proposals to restrict abortion and contraception throughout the United States. Trump claimed credit for overturning Roe but criticized Republicans pushing for total abortion bans. Trump said he would leave the issue of abortion for the states to decide but would allow red states to monitor women's pregnancies and prosecute them if they have an abortion.
Sources: en.wikipedia.org
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.
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.
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.
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.