Peptide Health Lab

Growth hormone axis

CJC-1295

FOR RESEARCH PURPOSES ONLY

Also known as: CJC-1295 with DAC, DAC:GRF, hGRF(1-29) albumin bioconjugate

Regulatory status
Research only
Evidence grade
Anecdotal reports only

Last reviewed August 2, 2026 · 11 sources

What CJC-1295 is and how it works

CJC-1295 is a synthetic analog of growth-hormone-releasing hormone, the hypothalamic signal that tells the pituitary to make and release growth hormone. It is built from the first 29 amino acids of human GH-releasing factor, the fragment that carries the biological activity, with four amino-acid substitutions and a maleimide group added at the C-terminus.[1]

That maleimide group is the whole point. After injection it reacts with a free thiol on circulating serum albumin and forms a covalent bond, so the peptide stops behaving like a peptide with a few-minute half-life and starts behaving like albumin, which persists for weeks. In the originating rat work, three albumin conjugates were compared. The best of them was designated CJC-1295; it produced a fourfold larger GH response than unmodified hGRF(1-29) and remained detectable in plasma beyond 72 hours.[1] In healthy humans the estimated half-life was 5.8 to 8.1 days.[2]

The mechanism is not speculative in the way that many research-peptide mechanisms are. GHRH receptors on pituitary somatotropes are well characterized, and a longer-lived agonist at that receptor producing more GH is a predictable pharmacological result rather than a proposed one. What is speculative is everything downstream of that: whether more GH and more IGF-1, produced this way, in people who are not GH-deficient, does anything a person would want.

A naming problem sits on top of all of this, it runs the opposite way from what most readers assume, and it decides what the evidence below is evidence about. The molecule in every published study on this page is the albumin-binding bioconjugate: the one carrying the maleimide group, sold and discussed as CJC-1295 with DAC, where DAC stands for drug affinity complex. In the analytical and doping-control literature the bare name "CJC-1295" and "CJC-1295 with drug affinity complex" are handled as two distinct target peptides, and the bare name is the unconjugated 29-amino-acid peptide, the molecule also sold as CJC-1295 without DAC or modified GRF(1-29).[10] When a national doping-control laboratory sequenced an unknown seized preparation, what it found was the unconjugated form: a 29-amino-acid peptide with a C-terminal amide, consistent with material marketed under the CJC-1295 name.[6]

The consequence is blunt and it should be read before anything below. No published human study has administered the unconjugated peptide. Every human result on this page was generated with the DAC bioconjugate: the growth-hormone and IGF-1 rises, the multi-day half-life, the pulsatility observation, the proteomic changes. That molecule's entire pharmacological character comes from binding covalently to albumin and persisting for days. A peptide without that group does not behave that way and has no human evidence of its own. Two molecules sharing a name is not a labeling quirk here; it is the difference between a compound with two small human pharmacology studies and a compound with none.

What the research actually shows

Two small human pharmacology studies, both with hormone-level endpoints. The registrational-style work here is two randomized, placebo-controlled, double-blind ascending-dose trials in healthy adults aged 21 to 61, running 28 and 49 days. Single subcutaneous injections produced dose-dependent increases in mean plasma GH of two- to tenfold lasting six days or more, and increases in mean plasma IGF-1 of 1.5- to threefold lasting nine to eleven days. After repeated doses, IGF-1 stayed above baseline for as long as 28 days. That is a cumulative effect. No serious adverse reactions were reported.[2]

Pulsatility was preserved, in one uncontrolled study. Because physiological GH secretion is pulsatile and pulsatility is thought to matter for GH's effects, a separate non-randomized study sampled healthy men every 20 minutes overnight before and one week after a single injection. Pulse frequency and amplitude were unchanged; trough GH rose roughly 7.5-fold, mean GH by 46%, and IGF-1 by 45%. The IGF-1 rise did not correlate with any measured parameter of GH secretion.[4] A later proteomic analysis in eleven healthy men found reproducible serum protein changes a week after injection, which is further confirmation that the axis was engaged, not evidence of benefit.[5]

Animal work is a deficiency model, not a performance model. In mice with the GHRH gene ablated, once-daily CJC-1295 for five weeks normalized body weight and length and kept relative lean and subcutaneous fat mass normal; dosing every 48 or 72 hours produced partial catch-up only.[3] That is a study of correcting an engineered hormone deficiency in growing animals. It does not address what happens when a hormonally normal adult raises an already normal axis.

Why people actually use it is documented, and it is not from trials. The one peer-reviewed account of real-world use is a qualitative study of bodybuilding forum threads, in which the stated motivations were weight loss, muscle enhancement, youthful skin, improved sleep, and injury healing, and in which participants openly discussed unresolved questions about dosing, cycling, and long-term effects.[7]

Where the evidence is weak

Not one clinical outcome has ever been measured. Every human study of CJC-1295 has hormone concentrations or plasma protein profiles as its endpoint. There is no published trial reporting body composition, strength, recovery from injury, sleep architecture, skin quality, or any other outcome a person would notice. The distance between "IGF-1 went up" and "something improved" is the distance this compound's evidence base has never crossed, and it is why the compound-level grade on this page reflects the claims people make for it rather than the pharmacology that is genuinely established.

The human evidence base is tiny and is roughly two decades old. A few dozen volunteers across a handful of studies, most of them conducted or sponsored in the mid-2000s during a development programme that did not proceed to approval. Nothing in the intervening years has replaced it. A 2026 independent review of peptides marketed direct to patients characterizes the human safety and efficacy data for unapproved compounds in this class as scarce, and explicitly warns about the potential for harm.[11]

Longest human exposure on record: seven weeks. Sustained elevation of GH and IGF-1 is the intended effect, and the consequences of sustaining it for months or years are unstudied. The epidemiological literature is not reassuring on this point in a general way: higher circulating IGF-1 is associated with the risk of several cancers in large prospective cohorts, most consistently prostate cancer.[8][9] That work describes naturally varying IGF-1 in people taking nothing, and it cannot be read as a measured risk of this compound. It is, however, the reason the malignancy question belongs in a clinician conversation rather than a forum thread.

Identity and purity are unresolved for anything sold under this name. With no approved manufacturer there is no assay standard, no release specification, and no lot testing. The published analytical work exists precisely because investigators had to determine what was actually in a preparation carrying this name. What they found was the unconjugated 29-amino-acid peptide, not the albumin bioconjugate the human trials used.[6][10]

A second molecule shares the name and has no human evidence at all. The compound sold as CJC-1295 without DAC, or modified GRF(1-29), has never been administered in a published human study. Every human number on this page belongs to the DAC bioconjugate. Applying those results to the unconjugated peptide is not a purity error; it is reasoning about a different molecule.[10]

Legal and regulatory status

CJC-1295 is not approved by the FDA for any indication, and no regulator has approved it anywhere. It is not a dietary supplement ingredient and it is not an approved drug; material carrying the name is distributed for laboratory research use, which is why every mention of it on this site carries research-only framing. It entered pharmaceutical development in the 2000s and did not complete that path.[2]

In tested sport the status is unambiguous, and it comes from the list rather than from an inference about it. The World Anti-Doping Agency names CJC-1295 by name as an example of a growth-hormone-releasing hormone analog under section S2.2.4, and every substance in section S2 is prohibited at all times, in competition and out of it, as a non-specified substance. The doping-control literature has treated it that way for years.[6] Detection is no longer theoretical: validated liquid chromatography–tandem mass spectrometry methods now identify CJC-1295 and its metabolites in urine at or below the required performance limits.[10]

What the regulatory status means for a reader is narrower and more useful than any debate about enforcement: there is no label, no approved manufacturer, no assigned indication, and no regulated quality standard behind anything sold as CJC-1295. PHL does not sell peptides and takes no position on how unapproved material reaches anyone.

Questions to bring to a provider

The useful conversation is not "should I run CJC-1295." It is "here is what I think is wrong or what I am trying to change. Is the growth-hormone axis actually involved, and how would we know?" Questions worth raising:

  • Is there any reason to think the GH/IGF-1 axis is abnormal here, and what testing would establish that rather than assume it?
  • Given that every published human study of this compound measured hormone levels and none measured an outcome, what would count as evidence that it did anything?[11]
  • Does a personal or family history of malignancy change the calculus, given the cohort associations between circulating IGF-1 and cancer risk?[9]
  • Would baseline and follow-up IGF-1, glucose, and a symptom review be enough to detect a change rather than assume one?
  • If competing in a tested sport, what does the current prohibited list say, and what are the consequences of a positive finding?[10]
  • For an unapproved compound with no manufacturer standard, how would anyone confirm that what is in the vial matches what the label claims?[6]

A clinician who answers "the human data stops at hormone levels" is describing the literature accurately, not being dismissive.

Evidence by claim

Grades describe how strong the evidence is; the line under each grade describes what kind of studies it is. How we grade evidence.

Growth hormone and IGF-1 elevation in healthy adults
Human RCT evidence human RCT · human observational

This is the compound's one genuinely strong claim. Randomized, placebo-controlled ascending-dose trials reported dose-dependent rises in mean plasma GH of 2- to 10-fold lasting six days or more and rises in IGF-1 of 1.5- to 3-fold lasting nine to eleven days, with an estimated half-life of 5.8–8.1 days. A later proteomic study in eleven healthy men confirmed downstream serum protein changes after a single injection. Both studies administered the albumin-binding DAC bioconjugate, the molecule sold as CJC-1295 with DAC, and the multi-day half-life is a direct consequence of that conjugation. Nothing in this entry applies to the unconjugated peptide sold under the same name as CJC-1295 without DAC or modified GRF(1-29), which no published human study has administered.

[2] [5]

Preservation of pulsatile GH secretion
Anecdotal reports only human observational

A single non-randomized study in healthy men reported that pulse frequency and amplitude were unchanged one week after injection while trough and mean GH rose. It is a small, uncontrolled, single-site observation that has not been replicated, and the authors could not correlate the IGF-1 increase with any parameter of GH secretion. It too used the DAC bioconjugate.

[4]

Restoration of growth in GH-deficient animals
Animal studies only animal

In mice with the GHRH gene ablated, once-daily CJC-1295 for five weeks normalized body weight and length and maintained normal lean and subcutaneous fat mass; dosing every 48 or 72 hours did not fully normalize growth. The originating chemistry work showed the same albumin-conjugation strategy producing a fourfold larger GH response than unmodified hGRF(1-29) in rats. Both are animal models of hormone deficiency, not of healthy adults seeking an effect.

[3] [1]

Body composition, recovery, sleep, or skin benefit in humans
Anecdotal reports only human observational · review

No published trial has tested any of these outcomes. The only peer-reviewed description of why people actually use the compound is a qualitative study of bodybuilding-forum discussion, in which the stated reasons were weight loss, muscle enhancement, youthful skin, improved sleep, and injury healing. Forum participants themselves raised unresolved questions about dosing, cycling, and long-term consequences. A 2026 review places CJC-1295 in the grey-market category where animal or mechanistic plausibility has not been matched by human outcome data.

[7] [11]

Long-term safety in humans
Anecdotal reports only human RCT · review

No study has followed anyone on this compound beyond seven weeks. What is published is a short-term absence of serious adverse reactions in a few dozen healthy volunteers, which cannot speak to uncommon or long-latency harms, and independent review characterizes the human safety evidence for unapproved peptides in this class as scarce.

[2] [11]

FOR RESEARCH PURPOSES ONLY

Typical protocol range in the research

  • Two randomized, placebo-controlled, double-blind ascending-dose trials in healthy adults aged 21–61, running 28 and 49 days, with hormone levels and pharmacokinetics as the endpoints

    Single subcutaneous doses across an ascending range, and multiple doses given weekly or every two weeks; the authors identified 30 and 60 µg per kilogram of body weight as the doses that were safe and relatively well tolerated [2]

  • Non-randomized clinical study of overnight growth-hormone pulsatility in healthy men aged 20–40, sampled before and one week after a single injection

    A single subcutaneous dose of 60 or 90 µg per kilogram of body weight; the two doses produced no significantly different response [4]

  • GHRH-knockout mice treated from one week of age for five weeks

    2 µg per animal at 24-, 48-, or 72-hour intervals; only the 24-hour interval normalized body weight and length [3]

Every published human dose above is expressed per kilogram of body weight and comes from a short pharmacology study whose endpoints were hormone concentrations, not a clinical outcome. No published trial establishes a dose of CJC-1295 for any human indication. The fixed weekly milligram figures that circulate in community discussion have no published trial behind them and are therefore not reported here.

Ranges are what published research reports, not a recommendation. PHL does not prescribe, and nothing here is personalized to you.

Side effects & safety signals

  • No long-term human safety data

    Not established · The only controlled human exposure ran 28 and 49 days and reported no serious adverse reactions. That is an absence of findings over weeks, not a finding of safety over years. A 2026 independent review of peptides marketed direct to patients in sports medicine states that rigorous human safety data for unapproved peptides including CJC-1295 are scarce and that there is potential for serious harm.

    [2] [11]

  • Sustained elevation of IGF-1

    Reported in every human study of the compound · After multiple doses, mean IGF-1 remained above baseline for up to 28 days. Separately, large prospective cohort work links higher circulating IGF-1 concentration to the risk of several cancers, most consistently prostate cancer. That association comes from people not taking anything and is not a demonstrated effect of this compound. Still, a personal or family history of malignancy is a reason to raise any growth-hormone-axis compound with a clinician before considering anything.

    [2] [8] [9]

  • Continuously raised trough growth hormone

    Observed one week after a single injection in healthy men · Pulse frequency and amplitude were unchanged, but basal (trough) GH rose roughly 7.5-fold and mean GH by 46%. Physiological GH secretion is pulsatile with low troughs; what a sustained non-pulsatile floor does over months has not been studied in humans, and the authors framed the finding as a mechanism question rather than a safety conclusion.

    [4]

  • Glucose and insulin: never measured in any human study of this compound

    Not characterized in any published human study · The two human studies of CJC-1295 had hormone concentrations and plasma protein profiles as their endpoints; neither reported fasting glucose, insulin, an oral glucose tolerance test, or HbA1c, and no other published human study of the compound has. That absence matters more here than it would for most entries, because the compound's characterized effect is a sustained, non-pulsatile growth-hormone floor, with trough GH roughly 7.5-fold above baseline a week after a single injection. Growth hormone is a counter-regulatory hormone that opposes insulin action. The result is not a documented interaction; it is an uncharacterized one, which is a different and in some ways less comfortable thing. Existing diabetes or prediabetes, or use of any glucose-lowering medication, is a provider-discussion flag before anything is considered, and independent review of unapproved peptides in this class describes the human safety data as scarce with potential for serious harm.

    [2] [11]

  • Unverified identity of material carrying this name

    Not quantified · A national doping-control laboratory asked to analyze an unknown preparation had to sequence it by mass spectrometry before it could say the contents were consistent with what is marketed as CJC-1295. The analytical literature also treats CJC-1295 and CJC-1295 with drug affinity complex as two distinct target molecules. With no approved manufacturer, nothing guarantees that a given vial holds the molecule its label names, at the concentration claimed.

    [6] [10]

  • Prohibited in tested sport

    Standing status · CJC-1295 is named on the World Anti-Doping Agency prohibited list itself, as an example of a growth-hormone-releasing hormone analog under section S2.2.4, and everything in section S2 is prohibited at all times, in competition and out of it. Detection methods now reach the required performance limits, so this is an enforceable status rather than a theoretical one. Any athlete in a tested sport should confirm the current year's list rather than rely on this page.

    [10] [6]

Published lists are never exhaustive, so report anything unexpected to a licensed provider.

Storage, handling & reconstitution

Lyophilized storage
Lyophilized CJC-1295 is conventionally kept refrigerated at 2–8 °C and protected from light, with freezing used for long-term holding. No published stability study addresses shelf life of the powder in a vial; the compound's published pharmacology concerns its half-life in circulation once bound to albumin, which is a different question entirely. The handling conventions here come from general lyophilized-peptide practice, not from a CJC-1295 study.
Reconstituted storage
Once in solution, peptides are conventionally refrigerated at 2–8 °C, protected from light, and treated as short-dated rather than indefinitely stable. No published study establishes a solution shelf life for CJC-1295.
Reconstitution diluent
The conventional diluent for lyophilized research peptides, including CJC-1295, is bacteriostatic water: sterile water preserved with 0.9% benzyl alcohol. Sterile water without a preservative is used where a preservative is contraindicated and is treated as single-use.
Reconstitution & handling
Conventional handling: sanitize the stopper before piercing it, add the diluent slowly down the inside wall of the vial rather than directly onto the powder, and let it dissolve on its own. Swirl gently if needed; never shake. A properly reconstituted solution is clear; anything cloudy, discolored, or carrying visible particulate is discarded. PHL does not publish volume or unit calculations, because those are dosing decisions and dosing decisions belong with a licensed clinician.
Handling notes
Because CJC-1295 has no approved manufacturer, there is no label, no assigned beyond-use date, and no lot-level stability testing standing behind any storage claim. Analytical work on seized preparations has found the name attached to material that had to be sequenced to be identified at all, so even the assumption that a vial contains what the label says is an assumption. Treat all of the above as convention, not specification.

The how-to guides cover the conventions behind these fields, and what the published stability data does and does not establish: Storage, Reconstitution, Handling.

Goal pages that include CJC-1295

Each one starts from the goal rather than the molecule, and grades what the evidence supports for that goal specifically.

  • Endurance

    A research reference for the compounds mapped to aerobic capacity and stamina. Every one of them is prohibited in tested sport at all times, and only one has a randomized human trial using an endurance endpoint.

  • Recovery

    A research reference for the peptides mapped to injury recovery and tissue repair, covering what the animal literature established, what the handful of human trials actually measured, and how to tell the two apart.

Questions for your provider

Bring this page to a licensed provider. A provider can order labs, review your medications and history, and tell you whether anything here is relevant to your situation. This page can't. Peptide Health Lab does not prescribe and does not sell peptides.

Want a structured starting point for that conversation? The Stack Builder turns your goals into a research-cited outline you can review together.

Citations

11 sources · every identifier checked against PubMed

Before you act on any of this

This page is educational only and is not medical advice. It does not diagnose, treat, or prescribe. Review it with a licensed provider before making any health decision. Peptide Health Lab does not sell peptides.

How we grade and verify evidence · Terms of Use · Privacy Policy

Open the Stack Builder