D tier · weak
It is the same peptide backbone as CJC-1295 with DAC minus the albumin linker, but stripped of that linker it has essentially no published human trial data of its own, and FDA stated it identified no pharmacokinetic data for the non-DAC form at all.
mod grf 1-29
Mod GRF 1-29 is the tetrasubstituted GHRH(1-29) analogue that forms the peptide backbone of CJC-1295, without the drug affinity complex that binds albumin. The four substitutions extend its half-life to at least about 30 minutes compared with under 10 minutes for unmodified GRF(1-29), but FDA's 2024 review identified no pharmacokinetic data and no clinical studies for the non-DAC form specifically.
// we supply this one
available as a research reagent
≥ 99% HPLC · lyophilised powder · batch certificate published. Grade D above is our own and is not adjusted because we stock it.
the explanation
Mod GRF 1-29 is CJC-1295 with the albumin-hook removed, so it is the same modified GHRH peptide but it clears in about half an hour instead of a week. It is one of the most widely sold compounds in this category and one of the least studied, because almost every published human trial used the DAC version instead.
regulatory status
Not approved; rejected for compounding
Never approved anywhere; FDA proposed at the 4 December 2024 PCAC meeting that CJC-1295 free base and CJC-1295 acetate, which are this molecule, NOT be included on the 503A Bulks List, stating no CJC-1295 form has been administered to subjects with a disease or condition.
how it works · proposed mechanism
Mod GRF 1-29 is a stability-engineered GHRH fragment that stops short of a depot formulation.
Same receptor as sermorelin
It binds the pituitary GHRH receptor and triggers cAMP-mediated GH synthesis and release, exactly as sermorelin and tesamorelin do. It is not a ghrelin-receptor agonist and does not act through GHS-R1a.
Four targeted substitutions
D-Ala at position 2 blocks the DPP-4 cleavage that inactivates native GHRH in minutes; Gln8 removes a deamidation-prone asparagine; Ala15 enhances potency; Leu27 removes an oxidation-prone methionine. Together they extend the half-life from under 10 minutes to at least about 30.
The DAC is what is missing
CJC-1295 with DAC adds a maleimidopropionyl-lysine at position 30 that covalently binds albumin. Mod GRF 1-29 lacks that residue entirely, which is the whole difference between a 30-minute peptide and a 6-to-8-day one.
Naming makes the literature unreadable
The 2005 paper introducing tetrasubstituted GRF(1-29) labelled it 'CJC-1295', and both molecules are sold under that name. FDA specifically flagged inconsistent nomenclature as complicating identification of which substance any given report refers to.
what’s reported
evidence shape
4 sourcesThe composition of the cited literature by study type. This describes the shape of the evidence, not its quality — and it does not by itself set the grade.
⚠ the catch
FDA's December 2024 review stated plainly that no pharmacokinetic data were identified for CJC-1295 free base, which is this molecule, and that the three published human studies of any CJC-1295 form all used healthy subjects rather than patients. Because vendors and the literature both use 'CJC-1295' for the DAC and non-DAC forms interchangeably, effects demonstrated for the week-long albumin-bound version are routinely and incorrectly attributed to this 30-minute peptide.
key published findings
- Regulatory review (FDA PCAC briefing, December 2024): FDA assigned CJC-1295 free base the formula C152H252N44O42, molecular weight 3367.95 g/mol and CAS 446036-97-1, and explicitly stated 'no pharmacokinetic data identified' for the free base form.
- Regulatory review (FDA PCAC briefing, December 2024): FDA identified only three published human studies of any CJC-1295 form (Ionescu 2006, Teichman 2006, Sackmann-Sala 2009), all in healthy subjects, and concluded 'no studies were found in which any form of CJC-1295 was administered to subjects with a disease or condition'.
- Chemistry (published characterisation of tetrasubstituted GRF(1-29)): the four substitutions D-Ala2, Gln8, Ala15 and Leu27 extend the half-life to at least 30 minutes versus under 10 minutes for the original GRF(1-29).
- Comparative pharmacokinetics (FDA review): CJC-1295 DAC remained detectable up to 72 hours after subcutaneous injection in rats while native GHRH(1-29) was detectable only up to 1 hour, illustrating that the albumin linker rather than the four substitutions accounts for the long duration attributed to 'CJC-1295'.
- Safety (FDA review): in vitro and in vivo studies of CJC-1295 substances demonstrated DNA damage in pituitary cells at tested concentrations, with dose-dependent injection-site irritation, inflammation and necrosis in animal studies.
limitations of the evidence
- There are no published human pharmacokinetic, pharmacodynamic or efficacy studies of the non-DAC form specifically; the frequently cited 30-minute half-life derives from the design rationale rather than a measured human curve.
- Nomenclature collision with CJC-1295 DAC means most claims made about this compound are borrowed from studies of a chemically different molecule.
- No repeat-dose toxicology, immunogenicity or carcinogenicity data exist for the non-DAC form, and FDA flagged missing reference standards and no USP monograph.
identity
| full name | [D-Ala2, Gln8, Ala15, Leu27]-human growth hormone-releasing factor (1-29) amide |
| category | Growth Hormone |
| modality | peptide |
| formula | C152H252N44O42 |
| molar mass | 3367.95 g/mol |
| cas | 446036-97-1 |
| half-life | At least ~30 min, versus under 10 min for unmodified GRF(1-29); no published human PK |
| sequence | Tyr-D-Ala-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Leu-Ser-Arg-NH2 |
laboratory handling
| storage | Lyophilised peptide is stored desiccated at -20°C or below, protected from light and moisture, for long-term laboratory storage; material in active use is held at 2-8°C. Reconstituted solution is kept at 2-8°C and used within a short window rather than refrozen. |
| solubility | Reconstituted with bacteriostatic or sterile water in laboratory settings; as a hydrophilic 29-residue peptide with no maleimide group it dissolves readily in aqueous buffer without organic co-solvent. |
| co-studied with | As a short-acting GHRH-receptor agonist it is the GHRH arm most often paired with GHS-R1a agonists in co-study designs, on the rationale that a pulse-matched GHRH signal and a ghrelin-mimetic signal delivered together produce greater somatotroph output than either alone. |
Handling information describes laboratory practice for a research reagent. It is not a preparation guide for use in humans.
the receipts
4 citedU.S. Food and Drug Administration · 2024 · official
U.S. Food and Drug Administration · 2024 · official
ChemicalBook · 2024 · official
Wikipedia (secondary summary of the 2005 CJC-1295 characterisation) · 2024 · tertiary
Sources marked tertiary or press release are the weakest citations on this page.
others in Growth Hormone