Description
Before ConjuChem bolted a maleimide linker onto the C-terminus and turned this peptide into a multi-day GHRH analogue, the underlying 30-residue molecule already had a name: Modified GRF 1-29, or Mod GRF 1-29 for short. That is the peptide on this page. Same four Sermorelin-stabilising residue swaps, same GHRH backbone, no DAC arm. The trade name CJC-1295 no-DAC stuck after the DAC variant entered clinical work, but the unlinked sequence predates it and remains the more widely cited tool compound in GH-axis assays.
The four substitutions and why they matter on their own
Native GHRH(1-29) falls apart in plasma within minutes. DPP-IV cleaves at position 2, while general endopeptidases chew through the backbone soon after. The substitutions D-Ala at position 2, Gln at 8, Ala at 15 and Leu at 27 close those gaps without touching the receptor-binding face. Result is a peptide that survives long enough in serum to act on the pituitary GHRH receptor and then clears, working half-life around thirty minutes by most published estimates. No linker, no albumin hitch, no carrier protein involvement.
Why short-acting is the point, not a limitation
The DAC version was engineered for sustained GH and IGF-1 elevation. This one was kept short on purpose. Endogenous GHRH fires in tight bursts every few hours, and pituitary somatotrophs respond differently to a square-wave hormone signal than to a brief spike. Mod GRF 1-29 reproduces something close to that natural pulse shape, which is the reason it became the standard pairing partner for GHRP-2, GHRP-6, Ipamorelin and Hexarelin in synergy studies. Most of the published CJC+GHRP synergy data, including the assays where the two classes hit the pituitary simultaneously and pushed GH output well above either compound alone, used this peptide rather than the DAC variant.
Technical sheet
- Sequence: GHRH(1-29) with D-Ala2, Gln8, Ala15, Leu27 substitutions
- Also known as: Modified GRF 1-29, Mod GRF 1-29, CJC-1295 without DAC
- Molecular formula: C152H252N44O42
- Molecular mass: approximately 3367.9 Da
- Purity: above 99% by reverse-phase HPLC, identity confirmed by mass spectrometry
- Format: lyophilised powder, sealed amber vial, nitrogen-flushed
At the bench
Sealed vials hold at minus twenty for extended storage. Reconstitute with bacteriostatic water and the working solution stays stable refrigerated for several weeks, though potency drift starts becoming measurable after about four. Avoid the freeze-thaw cycles that wreck most short GHRH analogues. Because there is no albumin-binding chemistry to wait on, in vitro pituitary cell assays show response within minutes of dosing rather than the lag seen with DAC-bearing peptides.
UK dispatch and sourcing
Synthesis runs through UK and EU facilities operating to GMP-equivalent process controls. Each batch carries its own HPLC trace and mass spec report tied to the lot number on the vial. UK orders placed before mid-afternoon reach roughly nine in ten postcodes inside 48 hours through Royal Mail Tracked 24. Send a CoA-fail photograph through live chat and a refund or replacement clears the same shift. Live chat is staffed by humans during UK business hours, not bots reading scripts.
Ten vials and up
Volume work past ten vials is quoted through the support inbox rather than the cart, partly because lots that size get reviewed for batch consistency first and partly to keep the pricing flexible.
Sold strictly for in vitro laboratory research. Not for human or veterinary use. UK 18+.
