GRF(1-29) comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-12-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
The two variants differ dramatically in how long they persist in circulation. The form lacking the albumin-binding group has a plasma half-life measured in tens of minutes, comparable to the natural hormone fragment. The version carrying the drug affinity complex binds albumin and shows a half-life of roughly six to eight days in human studies. That figure comes from small trials that tracked hormone levels over extended periods. The physiological consequences of sustained versus pulsatile stimulation are still debated and the literature does not settle the point.
Lyophilized peptide powder is comparatively stable when kept dry, cold, and protected from light. Once dissolved, the molecule is vulnerable to deamidation, oxidation, and aggregation, with the rate depending on pH, buffer composition, and temperature. Alkaline conditions and repeated freeze-thaw cycles accelerate loss of the intact peptide. The methionine present in the native sequence is a known oxidation site, which is one reason it was replaced in the modified fragment. Suppliers typically recommend cold storage of solutions and use within a short window.
Analytical confirmation usually relies on reversed-phase high-performance liquid chromatography for purity and on liquid chromatography coupled to mass spectrometry for identity. Mass data reveal the expected molecular mass and can flag truncated or oxidized species. Amino acid analysis and peptide mapping provide sequence-level verification. Immunoassays are used in some biological matrices, but antibodies raised against one releasing-hormone analog may cross-react with another. Reported purity figures depend heavily on the method used, so comparisons between suppliers require matching the analytical approach.
| Property | Value | Notes |
|---|---|---|
| Molecular weight (no linker) | ~3.37 kDa | Calculated from peptide sequence |
| Molecular weight (with linker) | ~3.65 kDa | Includes albumin-binding moiety |
| Appearance | White to off-white powder | Typically lyophilized |
| Solubility | Soluble in water | Also dissolves in aqueous buffers |
| Common synonyms | Modified GRF(1-29), DAC:GRF | Usage varies by source |
The distinguishing feature of the DAC form is a maleimide-containing group that reacts with the free thiol of cysteine-34 on human serum albumin. This reaction forms a covalent bond without enzymatic assistance, and it takes place after the peptide enters the bloodstream. Because albumin is abundant and long-lived, the attached peptide is carried through circulation far longer than an unmodified fragment would survive. The chemistry is a deliberate pharmacokinetic strategy rather than a change to receptor activity.
Enzymatic protection is a separate mechanism from plasma protein binding. The four substitutions in the backbone reduce recognition by dipeptidyl peptidase IV, which normally cleaves the natural hormone within minutes. Without the reactive group, this resistance still yields only a short window of activity, generally reported in the range of tens of minutes. With it, reported half-lives in early human work extended to several days. The size of that gap is the main practical distinction between the two materials.
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.
=== Chinese majors === On 16 September, the AQSIQ released test of samples from 491 batches of products sold by all 109 companies producing baby formula. It said all 11 samples from Sanlu failed the melamine test. Sanlu, whose products sell at half the price of equivalents on the market, recorded the highest levels of contamination among all the samples tested, at 2,563 mg/kg or parts per million ("ppm"). Tainted samples were found among 21 other suppliers, where concentrations ranged from 0.09 to 619.00 ppm. There was melamine contamination in 10% of liquid milk samples from Mengniu and Yili, and 6% of those from Bright Dairy. On discovery of contamination, the three major producers were all stripped of their status as 'Chinese national brands'. Yili, Mengniu and Bright Dairy & Food Co. recalled tainted powdered milk and apologised in separate statements. Mengniu recalled all its baby formula, and trading in its shares on the Hong Kong Stock Exchange was suspended on 17 September. Shares in other dairy companies fell strongly the next day. Mengniu's CFO attempted to reassure consumers by offering a no-quibble refund on all products, and by drinking liquid milk in front of reporters in Hong Kong. He also said that its export products were less likely to be contaminated. On 30 September, the AQSIQ announced test results of a further 265 batches of powdered milk produced by 154 different companies prior to 14 September, where it found 31 batches produced by 20 domestic dairy companies were tainted with melamine.
In mass spectrometry, matrix-assisted ionization (also inlet ionization) is a low fragmentation (soft) ionization technique which involves the transfer of particles of the analyte and matrix sample from atmospheric pressure (AP) to the heated inlet tube connecting the AP region to the vacuum of the mass analyzer. Initial ionization occurs as the pressure drops within the inlet tube. Inlet ionization is similar to electrospray ionization in that a reverse phase solvent system is used and the ions produced are highly charged, however a voltage or a laser is not always needed. It is a highly sensitive process for small and large molecules like peptides, proteins and lipids that can be coupled to a liquid chromatograph. Inlet ionization techniques can be used with an Orbitrap mass analyzer, Orbitrap fourier transform mass spectrometer, linear trap quadrupole and MALDI-TOF.
In April 2026, Moore signed Kanaiayah's Law, which establishes a guardianship assistance program and state foster youth ombudsman. In May 2026, Moore signed into law the No Kings Act, which allows Maryland residents to sue federal officials who violate another's constitutional rights under color of law.
Sources: en.wikipedia.org
CEEs are a combination of estrogens, or agonists of the estrogen receptors. The major estrogen in CEEs, sodium estrone sulfate, itself is inactive, and rather serves as a prodrug of estrone and then of estradiol. The transformation of estrone sulfate to estrone is catalyzed by steroid sulfatase, and of estrone into estradiol by 17β-hydroxysteroid dehydrogenase. CEEs (as Premarin) and estrone have been found to be equivalent in potency in an animal model of estrogenic activity. On the other hand, the active forms of the equine estrogens in CEEs, such as equilin and 17β-dihydroequilin, have greater potency in the liver relative to bioidentical estradiol, similarly to synthetic estrogens like ethinylestradiol and diethylstilbestrol. This results in disproportionate effects on liver protein production compared to estradiol, although to a lesser extent than ethinylestradiol and diethylstilbestrol. In addition, 17β-dihydroequilenin has shown a selective estrogen receptor modulator (SERM)-like profile of estrogenic activity in studies with monkeys, in which beneficial effects on bone and the cardiovascular system were observed but proliferative responses in breast or endometrium were not seen, although the clinical significance of this is unknown. CEEs consists of the sodium salts of the sulfate esters of equine estrogens in a specific and consistent composition (see the table). The major estrogens in CEEs are sodium estrone sulfate and sodium equilin sulfate, which together account for approximately 71.5–92.0% of the total content of CEEs.
== External links == Goudarzi, Sara (9 June 2006). "Yogurt Culture Evolves". LiveScience. Archived from the original on August 29, 2008. Retrieved 2013-01-14. Type strain of Lactobacillus delbrueckii subsp. bulgaricus at BacDive - the Bacterial Diversity Metadatabase "Lactobacillus delbrueckii". microbewiki.kenyon.edu – Microbe Wiki. Retrieved 2019-11-14.
In early 1984, just after South Africa and Angola had agreed to the principles of a peace settlement, UNITA had seized the opportunity to issue its own demanding conditions under which it would also accept the terms of a ceasefire. Savimbi requested a government of national unity with the MPLA in which he was granted a part, and threatened to begin attacking major cities if he was ignored. In this manner Savimbi sought to interlace conditionality over an SADF and FAPLA disengagement with his own conflict of interests with the Angolan regime. Although Botha approved of UNITA as an ostensibly anti-communist movement, he did nothing to impress Savimbi's demands on dos Santos. UNITA responded by raiding Sumbe, a settlement two hundred and sixty kilometres to the south of Luanda. That June, UNITA sabotaged the oil pipeline in Cabinda, kidnapping 16 British expatriate workers and a Portuguese technician. Six months later the insurgents raided Cafunfo, killing 100 FAPLA personnel. Most of these attacks were planned and executed from Jamba, a town in Cuando Cubango Province, which Savimbi had proclaimed UNITA's new national headquarters. Jamba had no prior strategic significance, possessed no agricultural base, and had limited access to fresh water, but it was located as far away from FAPLA bases as possible and within easy reach of SADF bases in Ovamboland and the Caprivi Strip. FAPLA had deserted the region for precisely this reason, withdrawing north after Operation Protea, but in the process left behind a power vacuum which Savimbi was quick to exploit.
Sources: en.wikipedia.org
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.
Early development used the albumin-binding form, and a shorter variant was later discussed under the same label. Because the two differ in half-life and handling, ambiguity arises whenever a source omits the variant designation.
The compound derives from that fragment but is not identical to it. The parent fragment lacks the stabilizing substitutions, so its degradation rate and duration of action differ noticeably.
The version carrying the affinity complex bears a maleimide group that binds serum albumin, which extends its circulation time to several days. The version without it lacks this group and clears within roughly half an hour. The two are chemically related but behave very differently once in the body.