
Sustained growth hormone release
In two placebo-controlled trials in healthy adults aged 21 to 61, growth hormone rose 2 to 10-fold for six days or more after CJC-1295.2

Modified GRF(1-29) with drug affinity complex (DAC)
CJC-1295 is a growth hormone signal fitted with an anchor that keeps it in the blood for days. The same name is sold for two quite different molecules, which is where most of the confusion starts.
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CJC-1295 is a modified form of growth hormone releasing hormone (GHRH) that prompts the pituitary gland to release the body’s own growth hormone. The version with DAC binds albumin in the blood and lasts about a week. It is studied for raising growth hormone and IGF-1, with evidence limited to small, short trials in healthy adults.
Medically reviewed by Robert Lufkin, MD (opens in a new tab)
Chief Medical Officer, Vitals Vault · Updated · 11 sources
CJC-1295 tells the body to release its own growth hormone, and it keeps telling it for days.
The signal tells the pituitary, a gland at the base of the brain, to release growth hormone. Rats showed a quick rise after injection.1
It bonds to a common blood protein, which shields it from breakdown. In healthy adults it lasted about 6 to 8 days.12
Growth hormone still came in pulses, but the low points between them rose. A week after one injection, average growth hormone was up 46%.3
Everything measured in people is a hormone level, in small trials of healthy adults. No study cited here shows changes in strength, fat loss or aging.
Tested in rat pituitary cells and in rats as a long-lasting, albumin-bound growth hormone signal.1
Shows a mechanism
In mice lacking the body’s own releasing hormone, the most frequent dosing kept growth normal over five weeks.4
Shows an effect in a body
Two small placebo-controlled trials in healthy adults raised growth hormone and IGF-1 for days. None measured muscle, fat or aging.23
Shows it works in people
The full guide to CJC-1295
The hormone behind CJC-1295 was first decoded from a tumor. In 1982, Roger Guillemin’s team isolated a 44-amino-acid peptide from a pancreatic tumor that had caused acromegaly, the condition of runaway growth hormone that enlarges the hands, feet and face. The tumor was making growth hormone releasing hormone, GHRH, the signal the hypothalamus normally sends to the pituitary.
GHRH had an obvious medical appeal and an obvious flaw. It prompts the pituitary to release its own growth hormone, which keeps the body’s feedback in charge, yet natural GHRH survives only minutes in the blood. Researchers found that its first 29 amino acids, called GRF(1-29), carry the full activity. That fragment became sermorelin. It was still short-lived.
Researchers at ConjuChem, a company in Montreal, tried a different trick. Besides making the peptide tougher, they gave it something to hold on to. In 2005 they described three versions of GRF(1-29) fitted with a reactive group designed to latch onto albumin, and picked the best one. They named it CJC-1295.
In rats, it was still circulating beyond 72 hours, and over the first two hours its growth hormone area under the curve was four times that of plain GRF(1-29). The question that followed was simple and important: what happens to the pituitary when the message to release growth hormone never quite stops?861
CJC-1295 starts as GRF(1-29) with four amino acids swapped, which makes it harder for enzymes to cut. The key addition sits at the end of the chain: a lysine carrying a maleimide group. This is the drug affinity complex, or DAC. After injection it forms a bond with a free sulfur group on serum albumin, the most abundant protein in your blood.
Picture a short-haul courier hopping onto a long-distance freight train. Albumin circulates for weeks, and while CJC-1295 is attached, it is shielded from DPP-IV, the enzyme that normally chops GHRH apart within minutes. The 2005 rat study saw CJC-1295 on the albumin band within 15 minutes of injection and still there a day later.
In people, the 2006 trials estimated a half-life of 5.8 to 8.1 days. During that time the peptide keeps reaching GHRH receptors on the pituitary’s growth hormone cells, which respond by releasing growth hormone. The liver answers that growth hormone by making IGF-1, the growth factor through which much of growth hormone’s effect runs.
So the chemistry is clever and the biology is ordinary. CJC-1295 does what natural GHRH does. It simply keeps doing it for days instead of minutes, which changes the shape of the signal the pituitary receives.12
The main human evidence comes from two randomized, placebo-controlled, double-blind trials published in 2006, lasting 28 and 49 days. The volunteers were healthy adults aged 21 to 61. The first trial tested single injections at four ascending doses. The second gave repeated injections over several weeks.
After one injection, mean growth hormone rose 2 to 10-fold and stayed up for six days or more, rising with the dose. IGF-1 rose 1.5 to 3-fold and stayed up for 9 to 11 days. After repeated injections, IGF-1 remained above baseline for up to 28 days, and the authors saw evidence of a cumulative effect.
No serious adverse reactions were reported, and the authors described CJC-1295 as safe and relatively well tolerated in those trials. They concluded it might be useful as a therapeutic agent. That conclusion fits what a short pharmacology study in healthy people can show.
These trials measured hormones, drug levels and short-term safety. They report nothing on muscle, fat, strength or sleep, and they enrolled healthy volunteers rather than people with low growth hormone, the group most people have in mind when they ask about CJC-1295.2
Growth hormone is normally released in bursts, with quiet troughs in between, and that rhythm matters for many of its effects. A drug that pushes the GHRH receptor around the clock might be expected to flatten the bursts into a steady hum. In 2006, a University of Illinois study checked.
Healthy men aged 20 to 40 had blood drawn every 20 minutes through a 12-hour night, once before and once a week after a single CJC-1295 injection. The pulses survived. Their number and size were unchanged. What moved was the floor: trough growth hormone rose 7.5-fold, mean growth hormone rose 46%, and IGF-1 rose 45%.
Think of the pituitary as a drummer who keeps the same beat no matter how loud the room gets. The rhythm is likely set by the push and pull of GHRH and somatostatin, the brake hormone, and a constant GHRH background did not override it. CJC-1295 raised the volume between beats while the beats themselves carried on.
The study held one more clue. The IGF-1 rise did not correlate with any measured feature of growth hormone secretion, yet the authors pointed to the higher trough as a likely contributor. If that is right, much of what CJC-1295 does may come from a steadier baseline of growth hormone. That remains a hypothesis from a small study, and it is the most interesting open question about this peptide.3
A 2006 study at Johns Hopkins asked what a long-acting GHRH analog can do when the body makes no GHRH at all. The researchers used mice with the GHRH gene removed. These animals grow poorly, and the team had previously found that even twice-daily injections of a short-acting GHRH analog could not bring their growth to normal.
CJC-1295 could. Over five weeks, young knockout mice on the most frequent regimen kept normal body weight and length, and relative lean mass and fat under the skin were normal in every treated group. Their pituitaries showed more growth hormone RNA and signs that growth hormone cells had multiplied. When the same amount was given with longer gaps between injections, growth improved but did not fully normalize.
The lesson is about exposure. Spacing the same injection further apart also meant less drug in total, so the study cannot separate timing from quantity. Still, a pituitary that sees GHRH for a few minutes at a time behaves differently from one that sees it most of the day. It is an animal finding about growth in a rare genetic deficiency, and it is useful mainly for what it says about how this class of drug works.4
Much of the confusion about CJC-1295 comes from the fact that the name is used for two molecules. The one in the published human trials is CJC-1295 with DAC, the albumin-binding version with a half-life of about a week. The other, marketed as CJC-1295 without DAC or Mod GRF 1-29, is described as keeping the four amino acid swaps and dropping the albumin-binding group. None of the studies cited here tested what those products contain.
Without DAC, the peptide has nothing to hold on to. Without albumin, it would be expected to clear far faster than the DAC form and give a much shorter exposure, though these studies never measured its human secretion pattern. It is best thought of as a sturdier cousin of sermorelin, and none of the human studies cited here tested it.
This matters because results do not transfer between them. The trough lift, the days-long IGF-1 rise and the safety record from 2006 all belong to the DAC version. Claims made online about one are often based on studies of the other, so the first useful question about any CJC-1295 product is which molecule it actually is.123
The measured effects of CJC-1295 in people are hormonal, and no clinical benefit was established. It raises growth hormone and IGF-1 for days after one injection, keeps natural pulses intact, and has a cumulative effect with repeated doses. In GHRH-knockout mice, it maintained normal growth.
One of the more unusual human studies used CJC-1295 as a research tool. In 2009, researchers analyzed blood proteins from 11 healthy young men before and a week after one injection, looking for new markers of growth hormone action. Their stated reason was that existing markers vary widely and do not reliably detect growth hormone abuse by athletes. They found shifts in several proteins, including an isoform of apolipoprotein A1.
What has not been measured is the list people usually care about: muscle, strength, fat loss, sleep quality, recovery and aging. Reviews of growth hormone secretagogues describe possible benefits for lean mass and sleep across the class, and also note that few long-term, rigorously controlled studies exist. None of the CJC-1295 studies cited here is one of those outcome trials.23457
In the 2006 trials, no serious adverse reactions were reported over several weeks in healthy volunteers. Those placebo-controlled trials are the controlled safety data cited here. They cover a small number of people for a short time and say nothing about long-term use.
FDA’s compounding safety page adds signals from outside those trials. It cites reported serious adverse events associated with CJC-1295, including increased heart rate and a systemic vasodilatory reaction, along with the risk of the body forming antibodies to the peptide and the difficulty of characterizing its impurities. FDA describes the available clinical data as limited.
A raised growth hormone floor for days at a time also has the familiar class concerns. Reviews of secretagogues report some rise in blood glucose from lower insulin sensitivity and say long-term evidence is limited, calling for more study of cancer incidence and mortality. Since growth hormone and IGF-1 promote cell growth, a personal cancer history calls for a careful conversation first.
The other practical risk is identity. With two molecules sold under one name and no approved product, what is in a vial bought online may not match its label. Anyone with diabetes, heart rhythm problems, low blood pressure, a pregnancy or tested-sport obligations should talk to a clinician before considering it.297
Growth hormone pushes blood sugar up by making tissues less sensitive to insulin, so metabolic labs come first. Fasting glucose is the quick snapshot. HbA1c averages your blood sugar over about three months and catches the slow drift a single reading misses.
Fasting insulin adds context. Higher insulin with steady glucose can be consistent with the pancreas working harder to hold the line, though on its own it does not diagnose insulin resistance and needs a clinician to interpret. hs-CRP, a liver-made marker of inflammation, gives a baseline for the background inflammatory load that tends to travel with visceral fat and insulin resistance.
IGF-1 deserves a mention even though it is a specialist test. It was the main readout in the 2006 trials, rising 1.5 to 3-fold after one injection and staying up for more than a week, so it is the most direct way to see how strongly your own axis is answering. A clinician can add it when growth hormone is the question.
Vitals Vault’s approach to peptide care starts with these numbers. A blood panel comes first, a licensed clinician reviews it with your history and decides what fits, and a retest of the same markers tracks how they move. Normal results are useful context, not proof that a peptide is safe.72
CJC-1295 has never been approved by FDA for any use. FDA’s compounding safety page lists it among nominated bulk substances with safety concerns, and it is not one of the six peptides covered by the October 2026 enforcement-discretion policy for 503A pharmacies.
In sport, the World Anti-Doping Agency prohibits growth hormone releasing factors, including GHRH analogs such as CJC-1295, in and out of competition.91011
CJC-1295 is a GHRH signal fitted with an albumin anchor. In healthy adults, one injection raised growth hormone and IGF-1 for about a week. In a separate overnight study, the quiet troughs between natural pulses rose while the pulses themselves carried on. The human studies cited here report hormone levels, drug levels, short-term safety and an exploratory look at blood proteins, all in small, short trials.
If you are weighing it, the question to start with is which molecule you are actually talking about, and then whether your growth hormone system needs a louder signal at all. Sleep, visceral fat and insulin all shape growth hormone release, and a baseline panel gives a clinician that metabolic context. It cannot diagnose low growth hormone, which takes a clinical evaluation and usually a stimulation test.23
In the 2006 trials, growth hormone rose within days of a single injection of the DAC version and stayed up for six days or more, while IGF-1 stayed raised for 9 to 11 days. Repeated injections had a cumulative effect on IGF-1. The version without DAC would act for a much shorter time.
Those are hormone timelines. None of these studies mapped how long any change in body composition or wellbeing would take. A sensible course starts with a baseline of glucose, HbA1c and insulin and ends with a retest of the same markers.2
Jetté et al., 20051
Laboratory and animal study · Rat pituitary cells and rats
Albumin-bound GRF(1-29) analog; 4-fold higher plasma growth hormone area under the curve over 2 hours than GRF(1-29); in plasma beyond 72 hours
Limits: Rats only
Teichman et al., 20062
Two randomized, double-blind, placebo-controlled trials · Healthy adults aged 21 to 61
Growth hormone up 2 to 10-fold for 6+ days; IGF-1 up 1.5 to 3-fold for 9 to 11 days; half-life 5.8 to 8.1 days
Limits: Hormone levels only; short; healthy volunteers
Ionescu and Frohman, 20063
Before-and-after sampling study · Healthy men aged 20 to 40
Pulses unchanged; trough growth hormone up 7.5-fold; IGF-1 up 45%
Limits: Small; one injection; no control group
Alba et al., 20064
Animal study, 5 weeks · GHRH knockout mice
The most frequent regimen kept weight and length normal; wider spacing improved growth without fully normalizing it; relative lean and fat mass normal in all treated groups
Limits: Genetic deficiency model in mice
Sackmann-Sala et al., 20095
Proteomic before-and-after study · 11 healthy young men
Changes in serum proteins, including an apolipoprotein A1 isoform, after one injection
Limits: Exploratory; no health outcomes
They share a name and four amino acid swaps. Only the DAC version binds albumin and lasts about a week, and the published human trials studied that version.12
In healthy men a week after one injection, pulse number and size were unchanged. The rise came from higher troughs between pulses.3
None of the human studies cited here measured muscle, strength or fat loss with CJC-1295. The human studies measured growth hormone, IGF-1 and blood proteins.25
The 2006 trials reported no serious adverse reactions in a short study of healthy adults. FDA cites reported serious events, including increased heart rate and a vasodilatory reaction, and long-term safety is poorly characterized.29
In the published trials, CJC-1295 with DAC was given as a subcutaneous injection every one to two weeks. A version without DAC would act far more briefly. Whether any prescriber would use either is a clinical decision, and neither is an approved product.2
CJC-1295 has no FDA-approved dose. Human trials gave healthy adults the long-acting version with DAC as single weight-based injections, or as a few doses spaced one to two weeks apart; the dosage table lists them. The version without DAC is far shorter acting and has no published human dose, so the two cannot be dosed alike. Your clinician sets your dose.23
CJC-1295 has no FDA-approved dose. In published human trials, healthy adults received the version with DAC as single weight-based injections, or two to three doses spaced a week or two apart, because it lasts about a week in the body. These are research doses, and a clinician sets the actual dose.
Already have a prescribed dose? The peptide dosage calculator turns it into the units to draw on an insulin syringe.
Human trial · Injection under the skin
30 or 60 µg/kg
Single dose; a second study gave 2 or 3 doses weekly or every 2 weeks2
Healthy adults aged 21 to 61; the best tolerated of the doses tested. CJC-1295 with DAC
Human trial · Injection
60 or 90 µg/kg
Single dose3
Healthy men aged 20 to 40; both doses raised IGF-1 by a similar amount. CJC-1295 with DAC
A clinician makes the call. These are the questions they will ask first.
Vitals Vault peptide care starts with a blood panel and a licensed clinician, and ends with a retest.
Get early access to peptide care| Attribute | CJC-1295 | Ipamorelin |
|---|---|---|
| Albumin-binding group | Yes, a maleimido lysine | No |
| Duration in humans | Half-life 6 to 8 days (2006 trials) | Short-acting, like other GHRH analogs |
| Growth hormone pattern | Pulses kept, troughs raised | Expected to be brief; not measured |
| Human trial data | Healthy adults, 2006 to 2009 | None in the studies cited here |
Most published human data are on CJC-1295 with DAC, the albumin-bound version. Much of what is sold online is a version without DAC, also called Mod GRF 1-29. The 2006 trials did not study it, and none of the studies cited here tested what those products contain.
Your own body also shapes the response. Sleep, body fat and insulin all change how the pituitary answers either version.13
A blood test before you start and a retest after shows what actually changed for you. It is how Vitals Vault approaches every treatment.
No. CJC-1295 is not FDA-approved for any use, and it is not one of the six peptides covered by the October 2026 enforcement-discretion policy. FDA’s compounding safety page lists CJC-1295 among nominated bulk substances that raised safety concerns, and cites immunogenicity risk, complexities with impurities and characterization, and reported serious adverse events including increased heart rate and a systemic vasodilatory reaction.910
2005
ConjuChem researchers identify CJC-1295 as a long-lasting, albumin-bound GRF(1-29) analog in rats.1
2006
Two placebo-controlled trials in healthy adults show sustained rises in growth hormone and IGF-1; pulsatility is shown to persist.23
2009
Proteomic study of serum after one injection looks for markers of GH and IGF-1 action.5
April 2026
FDA’s compounding safety page lists CJC-1295 with immunogenicity concerns and reported adverse events.9

CJC-1295 is studied for raising growth hormone and IGF-1. It is not FDA-approved to treat any condition.
DAC (drug affinity complex) is a maleimido lysine that bonds to albumin and extends the half-life to days. CJC-1295 without DAC, also called Mod GRF 1-29, keeps the four amino acid substitutions but not that group, so its effect is brief. The 2006 human trials studied the version with DAC.
In healthy adults it raised growth hormone and IGF-1 for days. No study cited here shows benefits for muscle, fat loss, sleep or aging in people.
It acts on the GHRH receptor in the pituitary to release growth hormone, and with DAC it keeps acting for days by riding on albumin.
The 2006 trials reported no serious adverse reactions. FDA cites reported serious events including increased heart rate and a systemic vasodilatory reaction, and long-term safety is poorly characterized.
There is no FDA-approved dose. Trials in healthy adults used single weight-based injections of the version with DAC, or a few doses a week or two apart. Your clinician sets your dose.
CJC-1295 mimics growth hormone releasing hormone. Ipamorelin mimics ghrelin. They act on different receptors on the same pituitary cells.
No. CJC-1295 is not FDA-approved for any use, and FDA’s compounding page lists safety concerns. It is not covered by the October 2026 policy.
It is not an approved drug and is not cleared for compounding by FDA’s October 2026 policy. Vials sold online as "research use only" are not made for people.
Yes. The World Anti-Doping Agency prohibits growth hormone releasing factors in and out of competition.
Vitals Vault is opening clinician-led peptide care that starts with a blood test. Join the peptides waitlist to hear first. A licensed clinician reviews your history and labs and decides whether CJC-1295 is right for you.

Vitals Vault is opening peptide care that starts with your blood work, is prescribed by licensed US clinicians and ends with a retest. Join the waitlist to hear first.