Mod GRF 1-29 is searched as if it had a dose, and it does not, at least not in any document that measured one. It is the growth-hormone-releasing fragment that CJC-1295 is built on, sold without the albumin-binding group that gives CJC-1295 its days-long action, and no human study of it has been published. This page records that absence with the searches behind it (run 2026-11-12), reports the forum figures a 2026 medical review set down, puts them beside the one approved molecule in the family, sermorelin, and does the unit arithmetic for the vials in circulation. It reports; it suggests no amount.
The difference between the two CJC-1295 forms, and the two 2006 trials of the DAC form, is set out on CJC-1295 DAC vs no DAC; the sermorelin label record is on the sermorelin dosage page. Any vial and water volume can be worked in the Mod GRF 1-29 calculator, and Medibact's Mod GRF 1-29 guide covers the molecule and what a purity report can establish.
One fragment, three products
Human growth-hormone-releasing hormone is a 44-residue peptide (UniProt P01286, residues 32–75 of its precursor, read 2026-11-12), and its first 29 residues carry the activity. That fragment, GRF(1-29), was approved in the United States as sermorelin (Geref) and is cleared from the blood within minutes: a 2026 review gives a disappearance half-time of about 4.3 minutes. Two lines of chemistry tried to make it last longer. One replaced four amino acids so that blood enzymes, chiefly dipeptidyl peptidase-4, cut it less quickly; Hoffmann-La Roche's 1990s work made several substituted analogues and, after adding a polymer chain to two of them, measured 12- to 55-fold the potency of the natural fragment in pigs and mice (Campbell et al., J Pept Res 1997, PMID 9266480). The other, at ConjuChem in Montreal, added a reactive lysine to a tetrasubstituted GRF(1-29) so that it would bond to albumin after injection; the company named that molecule CJC-1295 and found it in rat plasma beyond 72 hours (Jetté et al., Endocrinology 2005).
Mod GRF 1-29 is the middle product: the four substitutions, no albumin anchor. It is therefore expected to behave like sermorelin with better resistance to enzymes, not like the weekly DAC form. That expectation has not been tested in a published human study.
What the record holds
| Where | Search, 2026-11-12 | What came back |
|---|---|---|
| PubMed | "mod GRF", "modified GRF", "tetrasubstituted GRF", "CJC-1295" AND "without DAC" | No human study. Relevant records: the 2019 Copenhagen seizure analysis, the 2005 ConjuChem rat paper, the 2026 review; the rest were false matches (rice flour, foot orthoses, jump testing) |
| ClinicalTrials.gov | "CJC-1295"; "mod GRF" | 1 study (NCT00267527, ConjuChem, the long-acting molecule); 17 records for "mod GRF", all gonadotropin-releasing-hormone therapy studies matched on the letters, none about this peptide |
| PubChem | "Mod GRF 1-29", "modified GRF (1-29)", "CJC-1295 without DAC" | No compound record |
| Drugs@FDA, DailyMed | — | No product; the only approved GRF(1-29) product, Geref, is discontinued |
The 2026 review in Frontiers in Endocrinology (Dominikowski and colleagues, Poznan University of Medical Sciences) is the clearest statement of the gap. It sorts growth-hormone-axis peptides into four evidence tiers, from tesamorelin's randomised trials (tier A) down to compounds with no peer-reviewed human study at all (tier D), and places CJC-1295 without DAC in tier D alongside PEG-MGF and IGF-1 LR3. Its summary: the compound "remains essentially uncharacterised in the peer-reviewed human literature", and claims about it derive from extrapolation from sermorelin and from user reports.
Where the circulating figures come from
The review's Table 2 collects "self-reported online dosing patterns", which it describes as anthropological and behavioural data, not clinical recommendations. For Mod GRF 1-29 it records 100–200 µg per subcutaneous injection, one to two times daily, often combined with ipamorelin, preferably after strength training, in cycles of 12–16 weeks on and 4–6 weeks off. Vendor pages recorded on this site's peptide dosage chart on 2026-09-18 put the range slightly wider, 100 to 300 mcg one to three times a day. Neither source cites a measurement.
The combination with ipamorelin is the commonest context: the two act on different receptors in the pituitary, and blends are sold ready-mixed. What is and is not known about that pairing is on CJC-1295 + ipamorelin.
Per kilogram, beside sermorelin
Because sermorelin is the same fragment without the substitutions, its figures are the nearest documented reference. They come from a different population and a different purpose, so the comparison measures scale, not equivalence.
| Figure | Source | mcg/kg | For a 70 kg adult |
|---|---|---|---|
| Sermorelin treatment, once daily at bedtime | Geref regimen in growth-hormone-deficient children (as recorded on this site's sermorelin page) | 30 | 2,100 mcg |
| Sermorelin stimulation test, single IV dose | Geref diagnostic product (same page) | 1 | 70 mcg |
| Mod GRF forum range, per injection | 2026 review, Table 2 | 1.4–2.9 | 100–200 mcg |
The arithmetic is this site's. Two cautions apply. First, a tetrasubstituted analogue is built to survive longer in the blood, so a microgram of it may not do what a microgram of sermorelin does; no study has compared them in people. Second, the Geref treatment figure was a paediatric regimen for a deficiency, given to children, and does not describe adults without one.
What the vial holds
The 2019 Copenhagen analysis is the one laboratory finding specific to this compound. Powders seized by Danish customs were identified by high-resolution mass spectrometry as modified GRF 1-29, GHRP-2, GHRP-6 and ipamorelin, each with an extra glycine added at the start of the chain, a modification the existing doping-test methods were not looking for (Gajda et al., Drug Test Anal 2019). A glycine-extended molecule is a different molecule, with no record of its own; what a certificate of analysis can and cannot show about identity is covered in the Medibact guide linked above.
Units per vial
Vials are listed at 2, 5 and 10 mg. Concentration is the vial's micrograms divided by the water; one unit on a U-100 syringe is 0.01 mL.
| Vial and water | mcg/mL | mcg per unit | 100 mcg | 200 mcg | 300 mcg |
|---|---|---|---|---|---|
| 2 mg in 1 mL | 2,000 | 20 | 5 units | 10 | 15 |
| 2 mg in 2 mL | 1,000 | 10 | 10 units | 20 | 30 |
| 5 mg in 1 mL | 5,000 | 50 | 2 units | 4 | 6 |
| 5 mg in 2 mL | 2,500 | 25 | 4 units | 8 | 12 |
| 5 mg in 3 mL | 1,667 | 16.7 | 6 units | 12 | 18 |
| 10 mg in 2 mL | 5,000 | 50 | 2 units | 4 | 6 |
| 10 mg in 3 mL | 3,333 | 33.3 | 3 units | 6 | 9 |
At the higher concentrations, 100 mcg is two units, where a half-unit misreading is a quarter of the amount. More water gives larger, easier-to-read volumes for the same micrograms; how to read the scale is on insulin syringe units, and portions per vial for any amount on doses per vial.
What is not established
- Any human pharmacokinetic figure: half-life, peak, duration of the growth-hormone response.
- Any effect in people, on growth hormone, IGF-1, body composition or anything else.
- Whether one microgram is equivalent to one of sermorelin or of the DAC form.
- The safety of repeated daily use. The 2026 review lists the class signals reported for growth-hormone-axis peptides — fluid retention, joint and muscle pain, glucose changes, injection-site reactions — and notes that for tier-D compounds none of these has been characterised.
It is not an approved medicine in the United States, where no product of it has ever been listed. A clinician is the person to discuss growth-hormone testing or treatment with.