purity raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Pharmacokinetic behaviour differs sharply between the two forms. The DAC-bearing peptide shows an extended circulation time measured in days, whereas the version without the complex is cleared within roughly half an hour. This gap shapes how researchers design dosing schedules in animal models. Whether the prolonged presence of the DAC form produces effects meaningfully different from the short-acting variant remains an open question, since comparative human data are scarce.
CJC-1295 is a synthetic peptide designed to mimic growth hormone-releasing hormone (GHRH), the endogenous signal that prompts the pituitary gland to release growth hormone. The compound is a modified fragment of the natural hormone, spanning the first twenty-nine amino acids of GHRH with several substitutions that slow enzymatic breakdown. Two variants circulate in research settings: one carrying a drug affinity complex (DAC) and one without it. The DAC-free form is frequently labelled Mod GRF(1-29) in catalogs and discussion forums.
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 (with DAC) | ~3647 Da | Calculated from the full amino acid sequence |
| Molecular weight (without DAC) | ~3368 Da | Mod GRF(1-29) variant |
| Appearance | White lyophilized powder | Typical form supplied for research |
| Solubility | Soluble in water | Dissolves in aqueous buffers |
| Receptor target | GHRH receptor | Expressed on pituitary somatotroph cells |
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.
The compound emerged from work at a Canadian biotechnology firm in the early 2000s. Early human studies examined its effect on growth hormone and insulin-like growth factor 1 in healthy volunteers and in people with HIV-associated fat redistribution. Reports described sustained increases in both markers after a single injection. Development did not advance to regulatory approval, and the clinical programme was later discontinued. The molecule is now encountered mainly as a research chemical rather than a marketed medicine.
Two forms circulate in research settings and are frequently confused. One carries the drug affinity complex and is often written as CJC-1295 with DAC; the other lacks that group and is usually called modified GRF(1-29). The two share the same core sequence but differ sharply in how long they persist in blood. Products labelled only as CJC-1295 normally refer to the version carrying the complex. Documentation that omits the distinction leaves the intended molecule ambiguous.
CJC-1295 is a synthetic peptide built as a long-acting analogue of growth hormone-releasing hormone. Its backbone matches the first twenty-nine residues of the natural human hormone, with four amino acid substitutions added to slow enzymatic breakdown. A reactive maleimide group, commonly termed the drug affinity complex, allows the peptide to attach to circulating albumin after administration. That albumin attachment keeps the molecule in the bloodstream for an extended period instead of being cleared within minutes.
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.
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.
. In normal liquids, most of this crossover takes place at frequencies between GHz and THz, sometimes called hypersound. At sub-GHz frequencies, a normal liquid cannot sustain shear waves: the zero-frequency limit of the shear modulus is 0. This is sometimes seen as the defining property of a liquid. However, like the bulk modulus K, the shear modulus G is also frequency-dependent and exhibits a similar crossover at hypersound frequencies. According to linear response theory, the Fourier transform of K or G describes how the system returns to equilibrium after an external perturbation; for this reason, the dispersion step in the GHz to THz region is also called relaxation. As a liquid is supercooled toward the glass transition, the structural relaxation time exponentially increases, which explains the viscoelastic behavior of glass-forming liquids.
The Lewis S. Rosenstiel Award for Distinguished Work in Basic Medical Research is awarded by Brandeis University. It was established in 1971 "as an expression of the conviction that educational institutions have an important role to play in the encouragement and development of basic science as it applies to medicine". Medals are presented annually at Brandeis University on the basis of recommendations of a panel of scientists selected by the Rosenstiel Basic Medical Sciences Research Center. Awards are given to scientists for recent discoveries of "particular originality" and "importance to basic medical research". A $30,000 prize and a medallion accompanies each award. The Rosenstiel Basic Medical Sciences Research Center, named after Lewis Solon Rosenstiel, was established in 1968, carrying out research in basic medical science.
== Structure and variations == The amino acid sequence is reasonably highly conserved among mammalian species, with the native human sequence being YQPPSTNKNTKSQRRKGSTFEERK or Tyr‑Gln‑Pro‑Pro‑Ser‑Thr‑Asn‑Lys‑Asn‑Thr‑Lys‑Ser‑Gln‑Arg‑Arg‑Lys‑Gly‑Ser‑Thr‑Phe‑Glu‑Glu‑Arg‑Lys. However, there are also several other splice variants of IGF-1 aside from MGF. Multiple forms of MGF are used in scientific research such as the native mouse or rat form which have several amino acid changes, or a consensus sequence mainly based on the human sequence but with the arginine changed to histidine at position 23 and sometimes other substitutions, to more closely resemble the rodent version. Since mechano growth factor is rapidly metabolised in vivo, synthetic versions often use two or more unnatural D-amino acids in the central "QRRK" domain at positions 13-16 to improve metabolic stability, the tyrosine residue may also be PEGylated in these peptides.
=== Wa === John E. Walker FRS (b. 1941). British biochemist at Cambridge University, known for studies of ATPases and ATP synthase. Nobel Prize for Chemistry (1997). Foreign associate Natl. Acad. Sci. USA. Michael Wakelam (1955–2020). British molecular biologist at Babraham Institute, Cambridge Selman Waksman (1888–1973). Ukrainian-American biochemist at Rutgers University, known for discovering streptomycin and other antibiotics. Nobel Prize in Physiology or Medicine (1952). Christopher T. Walsh (1944–2023). American biochemist at Harvard, known for work on enzymes and enzyme inhibition, and especially for his book Enzymatic Reaction Mechanisms. Member Natl. Acad. Sci. USA. James C. Wang, (b. 1938). Chinese-American biochemist at Harvard, known for the discovery of topoisomerases. Member Natl. Acad. Sci. USA Xiaodong Wang, (b. 1963), Chinese-American biochemist at the National Institute of Biological Sciences, Peking, known for his work with cytochrome c. Member Natl. Acad. Sci. USA. Otto Heinrich Warburg FRS (foreign member) (1883–1970). German biochemist at the Kaiser Wilhelm Institute for Cell Physiology (Berlin), who pioneered the study of respiration. Nobel Prize in Physiology or Medicine (1931). Arieh Warshel (b. 1940). Israeli-American biochemist and biophysicist at the University of Southern California, a pioneer in computational studies on functional properties of biological molecules. Nobel Prize in Chemistry (2013). Member Natl. Acad. Sci. USA. Foreign member of the Russian Academy of Sciences. James D. Watson FRS (foreign member) (1928–2025).
Sources: en.wikipedia.org
== External links == ETH-LAD - Isomer Design ETH-LAD - PsychonautWiki ETH-LAD Experience Reports - Erowid The Big & Dandy ETH-LAD Thread - Bluelight ETH-LAD - TiHKAL - Erowid ETH-LAD - TiHKAL - Isomer Design ETH-LAD: A Powerful LSD-Alternative - Tripsitter ETH-LAD - Lysergamide Psychedelics - TripSitter
Both Portal games take place in the fictional "Aperture Science Computer Aided Enrichment Center". Aperture Science was founded by Cave Johnson (voiced by J.K. Simmons) and originally sought to make shower curtains for the military. Its research happened upon the discovery of portal technology, and soon became a direct competitor with Black Mesa Research Facility (from the Half-Life series) for government funding. Johnson acquired the rights to a disused salt mine in the Upper Peninsula of Michigan, where they started building a labyrinthine set of offices, laboratories, facilities, and test chambers. During this time, Johnson became poisoned from exposure to moon dust, a key component of the paint needed to support portal technology, and became increasingly deranged. In Portal 2, the player explores these long-abandoned areas of Aperture, learning that the company had moved from testing on the country's finest, to paid volunteers, who were often homeless, and ultimately to coercing its own employees to participate in testing. Leading up to his death, Johnson ordered his lifelong assistant Caroline (voiced by Ellen McLain) to be the first test subject for a mind-to-computer transfer; her personality would ultimately form the core of GLaDOS (also McLain). Some time after Johnson's death, the old sections of the facility were vitrified, and a more modern facility was built atop the ruins.
==== Supramolecular ==== Streptavidin or avidin in combination with biotinylated artificial metal cofactors is the most commonly used supramolecular strategy to make ArMs. In the early example from Ward et al. shown below, the ligand of Ru(I) complex was covalently linked to biotin and then the whole complex was anchored to streptavidin thanks to a specific and strong biotin-streptavidin interaction. The formed ArM can catalyze the reduction of prochiral ketones. Taking advantages of protein evolvability, different mutants of streptavidin can achieve different stereoselectivity. Throughout the years, many streptavidin-based enzymes were developed, enabling catalysis of very complex transformations in water, under ambient conditions. Besides biotin-streptavidin based ArMs, another important example of using supramolecular iassembly strategy is antigen-antibody recognition. First reported in 1989 by Lerner et al.., a monoclonal antibody-based ArM is raised to hydrolyze specific peptide.
Sources: en.wikipedia.org
==== United States ==== In the United States, 2C-B is classified as a Schedule I controlled substance. This became permanent law on June 2, 1995, following a proposal by the Drug Enforcement Administration in December 1994.
In the anterior pituitary, the term "acidophil" is used to describe two different types of cells which stain well with acidic dyes. Somatotrophs, which secrete growth hormone (a peptide hormone) Lactotrophs, which secrete prolactin (a peptide hormone) When using standard staining techniques, they cannot be distinguished from each other (though they can be distinguished from basophils and chromophobes), and are therefore identified simply as "acidophils". Eosinophilic Acidophile (histology) Basophilic Chromophobe cell Melanotroph Chromophil Basophil cell Oxyphil cell Oxyphil cell (parathyroid) Pituitary gland Neuroendocrine cell
In double knockout STAT2 mice, an increased proliferation of M1, M2, and M1/M2 coexpressing macrophages during influenza-bacterial super-infection is observed. The bacterial clearance was also impaired by neutralization of IFN-γ (M1) and Arginase-1 (M2) what suggests that pulmonary macrophages expressing a mixed M1/M2 phenotype promote bacterial control during influenza-bacterial super-infection. Therefore the STAT2 signaling is associated with suppressing macrophage activation and bacterial control during influenza-bacterial super-infection. These mice demonstrate no developmental defects. The knockout STAT2 and double knockout STAT mice in Vesicular stromatitis Indiana virus (VSV) model produce at least 10 times more virus plaque-forming units than the wild type (WT). IFN-α pretreatment supplied protection in WT and STAT2± cells but not in double knockout STAT2 cells. IFN-γ pretreatment did not provide any antiviral response during infection of VSV. This finding could be explained by the reduced level of STAT1 in cells of STAT2 knockout mice. Additionally, the double knockout STAT2 mice are more sensitive to mouse cytomegalovirus (MCMV), severe fever thrombocytopenia syndrome virus, influenza virus, dengue virus (DNV) and Zika virus than control mice, which suggests that STAT2 plays a critical role in the suppression of virus replication in mice.
Many journalists stated that the first "killer app" VR game was Half-Life: Alyx, developed by Valve and released in March 2020. Alyx includes a number of novel control schemes to avoid the motion sickness problems of previous VR games, such as the 2019 indie title Boneworks. Within a week of Alyx's announcement, Valve sold out of their stock of Index units and began taking pre-orders with expectations to fulfill before the game's release. Other VR hardware, including the Oculus, saw increased sales leading to the release of Alyx.
Sources: en.wikipedia.org
The synthetic peptide keeps the receptor-binding region of GHRH but carries substitutions that resist enzymatic cleavage. In the DAC version, an added group also anchors the molecule to albumin, extending its presence in the bloodstream.
The maleimide group forms a covalent link with albumin, an abundant blood protein. This attachment slows clearance, so a single administration persists much longer than the unmodified peptide. The feature is the main reason the two variants are handled differently in study design.
It is not an approved therapeutic product in major regulatory jurisdictions. It appears in research chemical catalogs and scientific literature rather than pharmacy shelves. Clinical development was limited and did not reach approval.
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.