What's on the label is the measured result — net peptide mass, not gross powder weight, plus RP-HPLC purity, on a lot-numbered COA for every batch.
Net peptide mass and RP-HPLC purity — a lot-numbered COA for every batch.
Net peptide mass + HPLC purity, per lot.
PCAC will review 7 peptides for the 503A bulks list, BPC-157, KPV, TB-500, MOTS-c, Emideltide, Semax, Epitalon. Read our briefing →
PCAC will review 7 peptides for the 503A bulks list. Read →
FDA PCAC reviews 7 peptides in July. Read →
Long-acting GHRH analog with Drug Affinity Complex
PeptideXpo buyer fit
This PeptideXpo page is intentionally positioned for distributors, OEM buyers, and procurement teams comparing CJC-1295 with DAC inside a wider peptide catalog. It is not trying to be the deepest single-molecule monograph; the differentiated intent is assortment planning, export-ready documentation, fill-size comparison, and whether this SKU belongs in a broader buyer program.
Overview
CJC-1295 with DAC is the long-acting variant of the Modified GRF 1-29 family, carrying a maleimido-propionyl group at Lys30 that allows covalent reaction with Cys34 of serum albumin in vivo, the Drug Affinity Complex (DAC) mechanism. The albumin conjugation dramatically extends plasma half-life from roughly 30 minutes (no-DAC) to approximately 6-8 days, supporting once-weekly dosing schedules in research and compounding contexts. PeptideXpo supplies CJC-1295 with DAC as the lyophilized acetate at ≥99.0% HPLC purity. The DAC variant requires more demanding analytical confirmation than the no-DAC form because the maleimido modification must be intact at the labelled position, partially hydrolyzed maleimide loses the in vivo albumin-binding activity even though it passes the standard HPLC purity gate at equivalent retention time. The release packet covers peak-integration HPLC plus ESI mass spec confirming the modified mass; intact-maleimide confirmation by reactivity assay against a reference thiol is available on request and is recommended at first-time supplier qualification. The DAC form's pharmacokinetic profile makes it more appropriate for sustained-elevation GH research and for compounding contexts where weekly dosing matters, while the no-DAC form is preferred for pulse-pharmacology research.
Who buys this, and why
GH-axis peptides ship to two main buyer types: compounding pharmacies dispensing under physician supervision, and research labs studying somatotropic-axis pharmacology. Pharmacies typically want sterile-filled vials with the full release packet (sterility, endotoxin, CCI); labs typically want bulk lyophilized powder with sequence verification. Blends (the CJC-1295 / Ipamorelin combination is the canonical example) are usually co-lyophilized rather than solution-mixed for potency stability.
Primary buyer fit: academic and contract research laboratories and 503A / 503B compounding pharmacies.
Specifications
Documentation available on request
Regulatory note
Sold as a bulk active for research and for compounding-pharmacy formulation where local regulations permit (notably 503A / 503B in the United States and analogous regimes elsewhere). Not a finished dosage form. Sterile-filled vials are available with full release documentation; the buyer is responsible for verifying scheduling and dispense requirements in the destination market.
Frequently asked questions
DAC stands for Drug Affinity Complex, the modification is a maleimido-propionyl group attached at Lys30 of the modified GRF 1-29 backbone. In serum, the maleimide reacts covalently with the free thiol of Cys34 on human serum albumin, creating a long-circulating peptide-albumin conjugate. Albumin's plasma half-life is roughly 19 days in humans, so the conjugated peptide circulates with similar kinetics, dramatically extended from the ~30-minute half-life of the unmodified no-DAC form. This is the same in vivo bioconjugation strategy used by several approved peptide drugs in other therapeutic areas.
The answer is about pharmacokinetic profile, not potency. Without DAC: ~30-minute half-life, pulsatile GH-release pattern, preserves natural pulse architecture, dosing every several hours. With DAC: ~6-8 day half-life, sustained GH elevation, suppresses natural pulse architecture, dosing once weekly. For research workflows studying pulse pharmacology or natural GH-release patterns, the no-DAC form is essential because the DAC version eliminates the pulse signal. For sustained-elevation research and for compounding contexts where weekly dosing is preferable to multi-times-daily, the DAC form is the right choice.
The DAC group's in vivo activity depends entirely on the maleimide remaining reactive, a hydrolyzed maleimide (which can form during storage or improper handling) loses the albumin-conjugation activity even though the molecule still passes the standard HPLC and mass-spec checks at very similar retention time and mass. The hydrolysis product is the open-ring carboxylic acid, which is chromatographically close to the intact maleimide but pharmacokinetically inactive. Reactivity assay against a reference thiol (cysteine or N-acetyl-cysteine) directly confirms the maleimide is intact, recommended at first-time supplier qualification and for any batch where stability is in question.
Related peptides
Modified GRF 1-29 · GHRH analog
Ghrelin / GHSR pathway GH-release peptide
29-mer
GHRH 1-29 fragment
