Research Only Growth Hormone Axis

Mod GRF 1-29

also known as: CJC-1295 without DAC, CJC-1295 no DAC, Modified GRF(1-29), Sermorelin analog

A short-acting GHRH analog — chemically identical to CJC-1295 but without the DAC albumin-binding linker — producing discrete GH pulses rather than sustained elevation.

The same four amino acid substitutions as CJC-1295 (D-Ala2, Gln8, Ala15, Leu27) applied to sermorelin's backbone, but lacking the DAC moiety — giving improved protease resistance over sermorelin while preserving pulsatile GH release kinetics.

Mechanism of action

GHRH receptor agonist. The four amino acid substitutions confer resistance to DPP-IV and other proteases, extending the functional half-life from ~7 minutes (native GHRH) to ~30 minutes while preserving the pulsatile GH-release profile that is considered more physiological than continuous stimulation. Typically stacked with ipamorelin or another GHRP.

Primary uses

Growth hormone axis research
Community "pulse" protocols stacked with GHRPs

Typical dosing

100–300 mcg 1–3 times daily (subcutaneous)

Community dosing only. No clinical standard exists for this specific variant.

Regulatory status

Not approved. Not distinct from CJC-1295 in the chemistry literature; the community treats "with DAC" and "without DAC" as two separate products, while vendors often label Mod GRF 1-29 as "CJC-1295 no DAC."

References

[pubmed] Alba M, et al. "Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse." Am J Physiol Endocrinol Metab, 2006.
[review] Walker RF. "Sermorelin: A better approach to management of adult-onset growth hormone insufficiency?" Clin Interv Aging, 2006;1:307-308.

Related peptides

CJC-1295

A long-acting GHRH analog engineered with a DAC linker that binds serum albumin, extending half-life from minutes to approximately 8 days.

Ipamorelin

A selective ghrelin receptor agonist that stimulates GH release without the cortisol, prolactin, or ACTH spike seen with older GHRPs like GHRP-6.

Sermorelin

The N-terminal 29 amino acids of native GHRH — a former FDA-approved diagnostic and pediatric GH-deficiency therapy, now widely compounded for adult anti-aging protocols.

Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.