Mod GRF 1-29 (CJC-1295 No DAC): Dosage, Reconstitution & Reading a Test Report

Mod GRF 1-29 at a glance

What it is

The tetra-substituted analog of GHRH(1-29) — the shortest fully active growth-hormone-releasing hormone fragment — without the DAC albumin-binding tag. Mod GRF 1-29, Modified GRF 1-29 and CJC-1295 no DAC all name the same molecule.

Human efficacy evidence

None indexed for the no-DAC form. PubMed contains no human efficacy trial of the tetra-substituted peptide without DAC; the one human CJC-1295 study (Ionescu & Frohman 2006) used the DAC version.

What the human CJC-1295 study actually dosed

60 or 90 mcg/kg as a single injection — about 4,200-6,300 mcg for a 70 kg adult, roughly 40-60x the ~100 mcg figure quoted for Mod GRF. The two doses did not differ significantly.

Commonly reported range

~100 mcg per injection is the figure the market repeats as a 'saturation dose'; reported protocols span roughly 100-300 mcg. No trial establishes this range for the no-DAC peptide.

Route reported

Subcutaneous injection in research and community reports.

Reported frequency

1-3 times daily in community protocols, on the reasoning that a short-acting GHRH analog has to be re-dosed to reach successive GH pulses.

Plasma half-life

No measured value has been published for this peptide. The ~30 minutes commonly quoted is an inference from DPP-IV resistance, not a measurement; for comparison, sermorelin's elimination phase has been measured at about 10.4 minutes.

Regulatory status

Not FDA-approved in any form. Prohibited in sport at all times by WADA under class S2. Research use only.

Reported ranges from research/community — examples, not recommendations.

What it is / mechanism

Mod GRF 1-29 is a synthetic analog of the first 29 amino acids of growth-hormone-releasing hormone (GHRH), the shortest fragment that retains full activity at the pituitary GHRH receptor. It carries four amino-acid substitutions — at positions 2, 8, 15 and 27 — introduced to resist cleavage by dipeptidyl peptidase IV (DPP-IV) and to reduce oxidation and deamidation, giving it more stability in solution than unmodified sermorelin. That tetra-substituted sequence is the molecule sold under two different names, and the naming split follows commercial history rather than chemistry. ConjuChem's CJC-1295 attached a Drug Affinity Complex (DAC) — a maleimide linker that bonds covalently to cysteine-34 of circulating serum albumin — to this same tetra-substituted GRF(1-29) backbone. Remove the DAC and what remains is Mod GRF 1-29. Suppliers, forums and study write-ups therefore use 'CJC-1295 no DAC' and 'Mod GRF 1-29' interchangeably, even though only one of those labels describes what is actually in the vial. The mechanism itself is uncontroversial and shared with every GHRH analog: binding the pituitary GHRH receptor raises cyclic AMP in somatotroph cells and triggers release of stored growth hormone, which in turn drives hepatic IGF-1 production. Because the release is of stored hormone into an axis that retains its own negative feedback through somatostatin and IGF-1, a GHRH analog amplifies the pattern of GH secretion rather than overriding it. What separates the two versions of this molecule is not the receptor interaction but how long the peptide stays in circulation to keep engaging it — and that is precisely the difference the DAC creates.

Researched effects

Reported effects in community and research-chemical contexts centre on growth-hormone release and downstream IGF-1: improved sleep quality, recovery and body composition are the usual claims. None of these has been tested in a controlled trial of the no-DAC peptide, and the claims should be read as reports of what people say they experience rather than as measured outcomes. What has been measured, in the DAC version, is narrower and more specific than the market summary suggests. In healthy men aged 20-40, a single injection of CJC-1295 (with DAC) increased mean GH by 46% and IGF-1 by 45% one week later, with the frequency and magnitude of GH pulses unchanged; what rose sharply — 7.5-fold — was the basal, between-pulse trough. The authors' conclusion was that continuous GHRH stimulation raises trough GH, and that this is what drives the IGF-1 increase. It is a real finding, and it is a finding about sustained exposure. A peptide cleared within an hour cannot produce a sustained trough elevation, so this result does not transfer to the no-DAC form even though the market routinely cites it as though it does.

Dosage — reported ranges (overview)

The figures below are what has been reported, not a recommendation and not a personal dose. The number that dominates community protocols is 100 mcg per injection, usually described as a 'saturation dose' — the amount above which additional peptide is said to produce no further GH release. It is worth being precise about where that figure stands. It is not drawn from a trial of this peptide, because no such trial exists. The nearest published anchor is the observation in the human CJC-1295 study that 60 and 90 mcg/kg produced no significantly different response, which is a plateau finding at doses roughly forty to sixty times larger, in the DAC-bearing molecule, at a single time point. Whatever the correct saturation dose for a short-acting GHRH analog is, that study does not establish it at 100 mcg. Reported protocols commonly describe 100-200 mcg per injection, occasionally up to 300 mcg, one to three times daily — most often before bed and at least a couple of hours away from food, on the reasoning that somatostatin tone and post-prandial insulin blunt the GH response. Cycles of roughly 6-12 weeks are described. Every element of that pattern is community practice reasoning from GHRH physiology, not a protocol any published study followed.

A printable protocol sheet with a reconstitution reference and an injection log comes with All-Access Lifetime.

Reconstitution — bac-water math

Reconstitution is concentration arithmetic and nothing else; the numbers below are not a personal dose. Mod GRF 1-29 is dosed in micrograms, so the useful figure is mcg per mL. Concentration is (vial mg x 1000) / mL of bacteriostatic water. On a U-100 insulin syringe, 100 units is 1 mL, so units to draw = dose (mcg) / concentration (mcg/mL) x 100. Worked example on the common 5 mg vial: adding 2 mL of bacteriostatic water gives (5 x 1000) / 2 = 2,500 mcg/mL. A 100 mcg reference amount is then 100 / 2500 x 100 = 4 units on a U-100 syringe. That is a very small draw, and it is the practical reason larger water volumes are used with this peptide: at 1 mL the same amount is 2 units, which is hard to measure accurately against the barrel graduations. Add water slowly down the vial wall, swirl rather than shake, and let the powder dissolve on its own.

This is concentration math, not a dose recommendation.

Injection / administration basics

In research and community reports Mod GRF 1-29 is described as a subcutaneous injection with a small-gauge insulin syringe, sites rotated, drawn to the calculated unit mark. Because the reference amounts translate to single-digit unit draws at ordinary concentrations, the measurement error at the syringe is proportionally large — a one-unit misread is a 25-50% error on a 2-4 unit draw. That arithmetic, rather than any pharmacological argument, is why higher reconstitution volumes are generally described for this peptide. This describes reported handling in a research context and is not instruction for personal use.

Half-life & frequency rationale

No published pharmacokinetic study reports a measured half-life for the tetra-substituted GRF(1-29) analog without DAC. This is worth stating plainly, because a specific figure — usually 'about 30 minutes' — circulates on essentially every commercial page about this peptide, presented as though it had been measured. What can be said is where the figure comes from. The four substitutions were introduced to block DPP-IV cleavage, which is the principal route by which native GHRH and sermorelin are degraded, so a longer plasma residence than sermorelin is a reasonable inference. Sermorelin's own pharmacokinetics have been measured: a two-phase profile with an initial phase of about 1.9 minutes and an elimination phase of about 10.4 minutes, against roughly 4.3 minutes for native 44-residue GHRH. A DPP-IV-resistant analog of that molecule plausibly persists somewhat longer. 'Somewhat longer than 10.4 minutes' is the honest statement; '30 minutes' is a number with no study behind it. The contrast with the DAC version is the part that matters for reading the literature. CJC-1295 with DAC is described at a half-life of about 8 days, because it is covalently tethered to serum albumin. That is not a modest difference in duration — it is the difference between a peptide that produces a transient pulse and one that produces the continuous stimulation whose effect on trough GH the 2006 study actually measured. Any claim about Mod GRF that is sourced to that study is a claim about a molecule with a half-life three orders of magnitude longer.

Stacking — overview

The pairing described almost universally is a GHRH analog with a ghrelin-receptor agonist — Mod GRF 1-29 with ipamorelin, or with GHRP-2 or GHRP-6. The rationale is mechanistic rather than trial-based: the two act at different receptors, and GHRH analogs plus GH secretagogues have been reported to produce a larger GH release together than either alone. That synergy is a real observation in GH physiology; it has not been demonstrated for this specific pairing in a controlled study. A point of frequent confusion is worth stating: Mod GRF 1-29 and CJC-1295 with DAC are not complementary partners, they are two versions of the same molecule. Combining them is combining a compound with itself at two durations, not stacking two mechanisms. The distinction is covered in more depth on the CJC-1295 guide.

For how combinations are grouped by research context, the named blends, and why a pre-mixed blend vial cannot be calculated from its total milligrams, see the peptide stacks guide.

Storage & handling

• Lyophilized vials are described as stored refrigerated at about 2-8 C and protected from light; the sealed powder is the stable form, and the four substitutions were chosen partly for stability in solution rather than in powder.
• After reconstitution, refrigerate at about 2-8 C, protect from light, do not freeze, and avoid shaking. Community handling reports generally describe use within two to four weeks of reconstitution; no stability study of this peptide in bacteriostatic water has been published, so that interval is practice rather than data.
• Bacteriostatic water is the diluent these figures assume — the benzyl alcohol is what makes a multi-dose vial a multi-dose vial rather than a single draw.

Evidence File

The Mod GRF Evidence File

The free guide names one human study, and its thesis is right. The record around that thesis is larger than the free page implies, and three public databases each hold something it does not mention. This module reads every dataset ever published in which this molecule family was given to human subjects, traces each circulating number back to the paper it came from and reports what that paper actually said, names the exact PubMed and registry queries that establish where the evidence for the untagged molecule stops, and follows what the sponsor did with its platform after the programme ended.

• 3 datasets gave the compound to humans, every one the tagged molecule
• 120-patient enrolment, 12 weeks, 0 results ever posted
• 3 different published half-lives for one compound
• 0 registered studies of the untagged peptide, in any status

Sourcing File

The Mod GRF Sourcing File

This compound has a verification problem that is specific to it and that no ordinary certificate addresses, and a second one that starts in the public chemistry database a laboratory would consult to check its work. This module fixes the identity numbers from PubChem and the FDA substance registry, recomputes every mass from the elemental formula, works through the adulteration mode documented in customs-seized material and three others with the arithmetic to catch each, computes what a salt load does to the amount actually drawn, and reads a certificate line by line with a verdict on every field.

• 0.0000 Da: the mass change of the substitution the molecule exists for
• +57.0215 Da: the adulterant documented in customs-seized material
• 85.6 mcg delivered from a draw calculated as 100 mcg
• 2 opposite molecules named on 1 public database record

Benefit & Outcome Review

The Mod GRF Benefit and Outcome Review

None of this is evidence about Mod GRF 1-29 itself, because no study has ever given the molecule to a human, an animal or a cell. Every marketed claim therefore has to be adjudicated on borrowed evidence, and the only honest way to do that is to say exactly how far each loan travels. This module sorts the record into three strict tiers, then works claim by claim through two nightly-injection trials of the closest published relatives, neither of which the free guide cites: months of dosing, absorptiometry body composition, quality-of-life scoring, and results that go several different ways.

• 0 studies in which this molecule itself was given to a human, an animal or a cell
• 19 subjects, 16 weeks: the closest placebo-controlled trial in the class
• Week 16: IGF-1 back toward baseline with nightly dosing still running
• 2 nightly-injection trials measured fat by absorptiometry; neither moved it

Guide FAQ

Quick answers about guide scope, access, and educational use context.