CJC-1295: research overview

The short version

CJC-1295 is a modified growth-hormone-releasing hormone (GHRH) analog that signals the pituitary gland to release more of the body's own growth hormone. It comes in two forms that behave very differently: a long-acting "DAC" version chemically bonded to a blood protein so it lasts for days, and a short-acting "no-DAC" version that clears the body within hours. The DAC linkage is an extra chemical conjugation step beyond a standard peptide synthesis, which adds real manufacturing cost and complexity — one reason the DAC and no-DAC forms are priced differently even though the core sequence is closely related. It has never been approved for human use anywhere.

What it is

A synthetic GHRH analog built on the first 29 residues of human growth-hormone-releasing factor, hGRF(1-29), carrying four amino-acid substitutions (D-Ala at position 2, Gln at 8, Ala at 15, Leu at 27) that stabilize the alpha-helix and block dipeptidylpeptidase-IV cleavage, deamidation and oxidation. In the DAC ('Drug Affinity Complex') variant a C-terminal lysine is functionalized with a maleimidopropionyl (MPA) linker that undergoes Michael addition with the free thiol on Cys34 of circulating serum albumin, forming a covalent peptide-albumin conjugate and extending the plasma half-life toward that of albumin itself. The no-DAC form ('Modified GRF 1-29') keeps the four substitutions but lacks the albumin-binding moiety and is therefore short-acting. CJC-1295 — CJC-1295 (tetrasubstituted hGRF(1-29) analog; DAC and no-DAC variants) It is classified as growth-hormone-releasing hormone (GHRH) analog (GHRH analog / growth-hormone secretagogue (research chemical; not approved for human use)).

How it works

CJC-1295 is a long-acting analog of growth-hormone-releasing hormone. It binds the GHRH receptor on anterior-pituitary somatotrophs, activating Gs/cAMP/PKA signaling that stimulates synthesis and pulsatile release of growth hormone, which in turn raises hepatic IGF-1. Four protease-resistant substitutions plus (in the DAC variant) covalent binding to serum albumin give it a multi-day half-life, so a single dose elevates GH and IGF-1 for days while preserving the pulsatile pattern of GH secretion.

What the research shows

A 2024/2025 Nature Reviews Endocrinology review synthesizes the pharmacology of GHRH and its synthetic analogues (the class that includes CJC-1295, sermorelin and tesamorelin), describing receptor signaling, the rationale for long-acting analog design, and their therapeutic and investigational landscapes. ^[18]

CJC-1295 was structurally identified by high-resolution LC-MS/MS as the active ingredient in an unknown 'GHRH' pharmaceutical preparation seized in an anti-doping context. ^[19]

In 11 healthy young adult men, CJC-1295 administration shifted the serum proteome (decreased apolipoprotein A1 and a transthyretin isoform; increased a C-terminal albumin fragment and immunoglobulin/beta-hemoglobin species), and the immunoglobulin/albumin-fragment signal correlated linearly with IGF-1, identifying candidate biomarkers of GH/IGF-1 axis activation. ^[20]

In healthy adults, single subcutaneous doses of 30 or 60 micrograms/kg CJC-1295 produced dose-dependent 2- to 10-fold increases in mean plasma GH for 6 days or more and 1.5- to 3-fold increases in IGF-1 for 9-11 days; after multiple doses IGF-1 remained above baseline up to 28 days, with an estimated CJC-1295 half-life of 5.8-8.1 days. ^[21]

In healthy 20- to 40-year-old men, a single subcutaneous dose of CJC-1295 (60 or 90 ug/kg) raised trough/basal GH approximately 7.5-fold and mean GH by ~46% and IGF-1 by ~45% one week later, while the frequency and magnitude of pulsatile GH secretion were unaltered, indicating GH pulsatility persists under continuous GHRH-analog stimulation. ^[22]

Reported effects, cautions & safety

Anecdotal, not clinical evidence — the reports below come from research-use communities and consumer write-ups, not from controlled human trials, and none of them describe a specific dose.

• Deeper, more restful sleep (very commonly reported): Better and deeper sleep is the single most commonly reported effect in research-use communities, and people often say it is the first thing they notice, sometimes within the first week. This fits the known biology, because growth hormone is released mainly during deep sleep. Reports describe falling asleep faster and waking less, though this is anecdotal and not from controlled trials.
• Faster recovery from training and soreness (frequently reported): Many users say they recover more quickly between hard workouts and feel less lingering soreness. This is one of the main reasons people in fitness communities seek the compound out. It is an anecdotal pattern, not a measured outcome, and recovery claims are easy to confuse with better sleep or simple training adaptation.
• Gradual fat loss, especially around the midsection (frequently reported): People commonly report slow, gradual loss of body fat over several weeks, most often around the belly, usually when the compound is paired with diet and exercise. Reports describe changes showing up around weeks three to six rather than quickly. These are personal accounts, not clinical measurements, and outcomes vary a lot between individuals.
• Leaner look and better muscle retention (frequently reported): Users often describe looking leaner or more defined and feeling that they hold onto muscle better while dieting. In the community this is usually framed as a slow, subtle change rather than dramatic muscle gain. It is anecdotal, and people frequently note it works only alongside consistent training and nutrition.
• Water retention, bloating, and puffiness (very commonly reported): Holding extra water is the most commonly reported downside, described as mild bloating, a heavier feeling, or puffiness in the hands and face. Communities widely note it is more pronounced with the long-acting CJC-1295 DAC form than with the short-acting no-DAC (Modified GRF 1-29) form, because DAC keeps growth hormone elevated for days. Most reports say it eases over a few weeks or with lower exposure.
• Tingling or numbness in the hands and fingers (frequently reported): Tingling, numbness, or pins-and-needles in the fingers and hands is a frequently reported complaint that people often compare to mild carpal tunnel. It is generally attributed to fluid retention pressing on nerves in the wrist. Reports describe it as dose-related and usually reversible when exposure is lowered.
• Injection-site reactions (frequently reported): Redness, itching, mild swelling, or soreness at the injection spot is a common report. These reactions are usually described as minor and short-lived. They are among the most consistently mentioned local effects in user discussions.
• Flushing or a warm 'head rush' after injecting (occasionally reported): Some users describe brief facial flushing, warmth, or a light-headed 'head rush' shortly after a dose. This is reported more with the short-acting no-DAC form right around injection time. It is generally described as passing within minutes, and it is an anecdotal observation rather than a measured effect.

What the safety literature flags:

• Not approved for human use anywhere ^[21] — CJC-1295 has never been approved by the FDA or any major regulator for people, and it is sold only as a research chemical.
• Sustained IGF-1 elevation and theoretical cancer risk — CJC-1295 raises growth hormone and IGF-1, and a large epidemiologic meta-analysis linked higher circulating IGF-1 to a modestly increased risk of certain cancers.
• Fluid retention, swelling, and nerve-compression effects — Growth hormone makes the kidneys hold onto sodium and water, which expands fluid volume.
• Effects on blood sugar and insulin sensitivity — Growth hormone is glucose-sparing, so sustained stimulation of the GH axis can reduce insulin sensitivity and raise blood sugar.
• Immunogenicity flagged by the FDA ^[18] — In 2024 FDA briefing materials for the Pharmacy Compounding Advisory Committee, immunogenicity (the risk the body forms an immune response to the peptide) and other safety concerns were cited as part of the basis for not recommending CJC-1295 for the 503A compounding bulks list.
• Discontinued development program and a cited patient death — The original long-acting CJC-1295 DAC program ran a Phase 2 trial in HIV-associated visceral obesity that was discontinued, and a patient death during the development era is frequently cited alongside the halted program.
• DAC and no-DAC forms are routinely confused — Marketing and forums often treat 'CJC-1295 DAC' and 'Modified GRF 1-29' (the no-DAC form) as the same thing, but they behave very differently: the DAC form stays active for days while the no-DAC form lasts only minutes to hours.
• Prohibited in sport at all times — CJC-1295 is banned by the World Anti-Doping Agency at all times under Section S2 (peptide hormones, growth factors, and related substances), and it is detectable with established lab methods.

Where CJC-1295 fits in research peptide economics

CJC-1295's two variants are a clean illustration of how one extra synthesis step changes cost. The no-DAC form ("Modified GRF 1-29") is a comparatively simple 29-residue peptide. The DAC form adds a linker chemistry that must covalently attach to serum albumin after the peptide leaves the body, and verifying that this conjugation step worked correctly is its own analytical-testing cost. Buyers sometimes see DAC and no-DAC priced close together, which is itself a signal worth scrutinizing, since the DAC form's added synthesis and verification work should, structurally, cost more to make well.