CJC-1295 Research Guide: GHRH Analog, DAC Technology, and Growth Hormone Axis Biology

By Justin Cartier

See how this fits the wider landscape of growth-hormone and muscle research peptides.

CJC-1295 is a peptide studied for one job: raising the body’s own growth hormone (GH). It gets there by binding the GHRH receptor in the pituitary gland. That tells the body to release more GH and, downstream, more IGF-1.^[1] But its real signature is staying power. The DAC version hangs around in the blood for about a week, so it only needs dosing once every seven days.^[2] This guide covers what CJC-1295 does and how DAC technology works. It also covers the DAC versus non-DAC split, how it pairs with ipamorelin, and what to check when sourcing it.

First, though, a point of confusion worth clearing up. The name actually covers two different peptides. The DAC version is the long-acting one. It latches onto a blood protein (albumin) and lasts roughly a week. The non-DAC version, also sold as Mod GRF 1-29, shares the same building blocks but drops the DAC part. So it clears in about 30 minutes. These are genuinely different compounds with different dosing, and suppliers don’t always spell out which is which. Mix them up and your data turns to mush. So always confirm which version a study actually used.

Research-use disclaimer: CJC-1295 is sold for laboratory research only. It isn’t a drug, supplement, or treatment. It isn’t for human use. The notes below describe published lab and research findings, not medical advice.

What does CJC-1295 do to the body?

It binds the GHRH receptor in the pituitary and sets off the body’s own growth hormone release. That GH then travels through the blood and drives IGF-1 production in the liver. Ionescu and colleagues, in the Journal of Clinical Endocrinology & Metabolism, found that CJC-1295 lifted baseline and average GH and IGF-1 while keeping the natural GH pulse pattern intact.^[1] Holding that natural pulse is really the key edge over just injecting GH, which steamrolls the body’s own rhythm.

From there, the higher GH and IGF-1 feed into more protein building in muscle. They also drive more fat breakdown across belly and under-skin depots, support bone, and shift which fuel the body reaches for. Sackmann-Sala and colleagues, in Growth Hormone & IGF Research, documented that whole GH/IGF-1 axis lighting up with GHRH analogs across research and clinical settings.^[3] That axis is the metabolic engine behind this class of peptide therapies.

DAC technology and the long half-life

The DAC, short for Drug Affinity Complex, is the clever bit that makes CJC-1295 last so long. Jetté and colleagues, in Endocrinology, showed the peptide was engineered into a stable, active GHRH(1-29) analog. They did it by tacking on a reactive maleimide group that latches onto albumin in the blood.^[4] Once it’s bolted to albumin, the peptide gets to ride along with that protein’s long lifespan instead of breaking down within minutes.

And the numbers are striking. Teichman and colleagues, in the Journal of Clinical Endocrinology & Metabolism, measured a half-life of 5.8 to 8.1 days in healthy human volunteers. Natural GHRH lasts about 30 minutes.^[2] That’s the longest half-life of any GHRH analog in use. It’s exactly what allows once-weekly dosing instead of the daily grind that sermorelin or tesamorelin demand.

CJC-1295 with DAC vs without DAC

Structurally, the two versions really only differ in that one detail. But it changes everything. The DAC form binds albumin, runs about a 6-day half-life, and gets dosed once a week. The non-DAC form (Mod GRF 1-29) uses the same building blocks minus the DAC. So it clears in roughly 30 minutes and needs dosing several times a day to hold a steady effect. That gap matters for study design. The DAC form gives a steady, near-flat GH rise across the whole week, which partly overrides the natural pulse. The non-DAC form delivers short, pulse-timed GH bursts that copy natural GHRH far more closely. Alba and colleagues, in the American Journal of Physiology, showed once-daily CJC-1295 kept normal body composition and growth in a GHRH-knockout model.^[5] Most research these days still leans on the once-weekly DAC version.

How CJC-1295 and ipamorelin work together

The CJC-1295 and ipamorelin pairing is the go-to research combination for body-composition work, and the logic is elegant. The two peptides hit completely different receptors. So their effects add up rather than step on each other. CJC-1295 binds the GHRH receptor and lifts the baseline of GH and IGF-1. Meanwhile ipamorelin binds the ghrelin receptor (GHS-R1a) and fires off the GH pulses. Run them together and you raise the floor and amplify the spikes at the same time. That copies natural GH release more closely than either could alone. Neither one’s mechanism sits inside the other’s, so the pair genuinely stacks. The one wrinkle is timing. CJC-1295 with DAC has about a 5-day half-life against ipamorelin’s roughly 2 hours. So ipamorelin needs dosing several times a day while CJC-1295 goes once a week. Pre-blended pens often combine set microgram amounts of each in a single injection.

Benefits of the CJC-1295 + ipamorelin stack

The benefits reported in research protocols cluster in a few places. You get a steady GH and IGF-1 rise across the dosing interval. You also get modest lean-mass gains over 8 to 16 weeks of steady dosing. Fat loss shows up too, especially on belly fat, which makes this pair a genuine fat loss peptide combination in practice. Alongside that, researchers note better sleep depth in line with the natural night-time GH pulse. They also note modest skin-elasticity gains tied to IGF-1-driven collagen, plus bone support in the longer protocols. The effect sizes stay modest next to injecting GH directly. But keeping that natural pulsing pattern is precisely what makes the pair a research alternative to direct HGH.

What effects does CJC-1295 produce?

The effects are gradual, not sudden. Reported research observations include better sleep depth and a mild early-week tiredness sometimes nicknamed “GH flu.” Researchers also note a small bump in appetite and slow body-composition shifts spread over months. There’s no quick high or stimulant kick here. The mechanism is slow hormone rebalancing rather than a brain-chemical surge. Some mild water retention and joint discomfort do turn up in the early weeks, right in line with low-dose GH effects.

Side effects and safety

Most of the reported side effects trace straight back to the GH and IGF-1 rise. The common one is injection-site reactions, running 5 to 15 percent. Next come brief water retention and limb swelling early in dosing, plus some mild joint stiffness during the GH-adjustment period. Rarer effects include carpal-tunnel-like symptoms at higher doses and a brief blood sugar rise, since GH opposes insulin. That sugar rise is usually not meaningful in non-diabetic subjects. There’s also a piece of history worth naming. The early CJC-1295 clinical program included one reported death linked to heart issues, which ended the original ConjuChem development. Later research and compounded use haven’t confirmed a clinical-grade heart signal. Still, that history is part of the caution that follows the compound around.

Dosage and administration

Research protocols split along the two versions. The DAC form typically runs 1 to 2 mg under the skin once a week. The non-DAC Mod GRF 1-29 runs 100 to 200 micrograms under the skin two to three times a day, often paired with ipamorelin. It comes as a freeze-dried powder that you mix with bacteriostatic water. Bedtime dosing is common, to line up with the natural night-time GH pulses. The pre-blended CJC-1295 and ipamorelin pen often delivers 100 micrograms of each in one shot.

How long to see results?

The GH and IGF-1 rises show up within days. The body-composition changes take longer, appearing over 8 to 16 weeks of steady dosing. Better sleep often gets reported within the first 2 to 3 weeks. Visible recomposition, meaning slow fat loss and slightly more muscle definition, usually takes 12 weeks or more.

Is CJC-1295 legal?

CJC-1295 has no finished-drug approval. It was placed on the FDA’s 503A “do not compound” list in 2023, and it sits on the World Anti-Doping Agency banned list. So it is sold only as a research-use-only chemical. Our guide to buying peptides in Canada explains what that framework means for researchers.

Red flags to watch for when sourcing CJC-1295

The warning signs of a bad batch matter more here than with most peptides, because two different compounds share the name. Start with the paperwork. Walk away if there’s no third-party analysis certificate keyed to the exact lot. Walk away too if the certificate is vague, with a purity number but no batch code. Distrust a lone HPLC figure like “98 percent” that comes with no chromatogram trace. The trace is what shows one clean peak instead of a spread of side-products. The decisive check is the mass, and this is where the DAC-versus-non-DAC mix-up gets caught. The DAC form has an expected weight near 3,647 Da. The non-DAC Mod GRF 1-29 lands near 3,368 Da. An MS readout near 3,368 Da on a vial sold as “CJC-1295 with DAC” is a clear red flag that you were shipped the short-acting peptide instead. For any in-vivo or cell-culture work, missing endotoxin and sterility data is the final deal-breaker.

Reviv Peptides supplies CJC-1295 with a third-party COA and HPLC purity confirmation, in both standalone and CJC-1295 + ipamorelin blend formats. View the CJC-1295 product page or the CJC-1295 + Ipamorelin Blend.

CJC-1295 questions

What does CJC-1295 do to the body?

It binds the GHRH receptor in the pituitary, raises the body’s own growth hormone, and drives IGF-1. Over months of steady dosing, the downstream effects include modest lean-mass gain, belly-fat loss, better sleep, and bone support.

What are the side effects of CJC-1295 and ipamorelin?

Injection-site reactions (most common), brief water retention, mild joint discomfort, occasional carpal-tunnel-like symptoms at higher doses, and a brief blood sugar rise. The historical CJC-1295 program included one reported death. Later research hasn’t confirmed a clinical-grade heart signal.

What effects does CJC-1295 produce?

They’re gradual: better sleep depth, mild early-week tiredness (“GH flu”) in the first 1 to 2 weeks, a small appetite increase, and slow body-composition shifts over months. No quick stimulant-like effect.

What is the difference between CJC-1295 with DAC and without DAC?

With DAC, you get about a 6-day half-life from albumin binding, once-weekly dosing, and a steady near-flat GH rise. Without DAC (Mod GRF 1-29), it’s about a 30-minute half-life and multi-daily dosing. You also get short pulse-timed GH bursts that copy natural GHRH more closely.

How do CJC-1295 and ipamorelin work together?

CJC-1295 raises baseline GH through the GHRH receptor, while ipamorelin fires GH pulses through the ghrelin receptor. The two hit different receptors and add up instead of overlapping. That copies natural GH release more closely than either alone.

Key data point: Teichman and colleagues (2006, JCEM) measured a CJC-1295 half-life of 5.8 to 8.1 days in healthy adults, against roughly 30 minutes for natural GHRH.^[2] That is the longest half-life of any GHRH analog in use, and the reason it can be dosed just once a week.

Summary

CJC-1295 is the GHRH analog with the longest blood half-life in research use, thanks to DAC-driven albumin binding. The DAC version supports once-weekly dosing. The non-DAC version copies natural GHRH with multi-daily dosing. Both raise the body’s own growth hormone through the pituitary GHRH receptor. That lifts IGF-1 and produces modest body-composition effects over months. The CJC-1295 and ipamorelin pair is the go-to research combination for recomposition, joining a baseline-raiser with a pulse-trigger. It isn’t approved as a finished drug. It was added to the FDA 503A “do not compound” list in 2023, and it is on the WADA banned list. So research-grade material stays available for laboratory research only under research-use-only labels.

Sources: [1] CJC-1295 raises GH and IGF-I with preserved pulsatility (Ionescu et al., 2006), PubMed. [2] Half-life of CJC-1295 in healthy adults, 5.8 to 8.1 days (Teichman et al., 2006), PubMed. [3] GH/IGF-1 axis activation by CJC-1295 (Sackmann-Sala et al., 2009), PubMed. [4] Identification of CJC-1295 as a long-lasting GRF analog via albumin binding (Jetté et al., 2005), PubMed. [5] Once-daily CJC-1295 normalizes growth in the GHRH-knockout mouse (Alba et al., 2006), PubMed.

Justin Cartier

The Reviv Peptides Research Team is a collective of science writers and researchers dedicated to producing evidence-based, peer-reviewed-grade content about research peptides. Our work focuses on molecular mechanisms, receptor pharmacology, and preclinical data — including GLP-1/GIP/glucagon incretin biology, growth hormone axis peptides (GHRH analogs and ghrelin-receptor secretagogues), mitochondrial-derived peptides (MOTS-c, SS-31), tissue-repair peptides (BPC-157, TB-500, GHK-Cu), and nootropic peptides (Semax, Selank). All content is written in a strict preclinical/laboratory context; none of our editorial material is intended as medical advice. Every guide is reviewed for scientific accuracy against published peer-reviewed literature.