Performance & GH axis
Mod GRF 1-29
CJC-1295 without DAC, Modified GRF (1-29), Sermorelin analogue
Mod GRF 1-29 is a modified fragment of growth hormone releasing hormone comprising its first 29 amino acids with four substitutions for stability. It is frequently confused with CJC-1295, which is the same peptide with a drug affinity complex attached. It is not approved for human use.
Also known as: CJC-1295 no DAC, CJC-1295 without DAC, Modified GRF 1-29, ModGRF1-29, GRF 1-29
- Status
- Mod GRF 1-29 is a research compound and not approved by the FDA for human use.
- Evidence
- Preclinical. Evidence comes from animal or lab studies; effects in people are not established.
- Half-life
- Roughly 30 minutes, in contrast to the multi-day half-life of the DAC-modified version.
- How it's taken
- Subcutaneous injection in non-clinical use
- Mechanism
- Growth-hormone secretagogue
- Pathways
- GH axis, GHRH analogue
How Mod GRF 1-29 works
GHRH(1-29) retains the full biological activity of the 44-amino-acid parent hormone. Four amino acid substitutions resist enzymatic degradation, chiefly by dipeptidyl peptidase-4. It binds the GHRH receptor on pituitary somatotrophs to stimulate growth hormone synthesis and release. Critically, without the DAC modification it does not bind albumin, so its action is short — producing a pulse rather than the sustained elevation ("bleed") of CJC-1295 with DAC.
What research has looked at
- A short-acting profile more closely mimics natural pulsatile growth hormone secretion than the sustained elevation produced by the DAC version, which is the usual argument for preferring it.
- GHRH receptor activity is well characterised, and the approved GHRH analogue tesamorelin demonstrates the axis is pharmacologically tractable.
- It acts through a different receptor from the GHRP family, so the two are commonly combined for a larger combined pulse.
Evidence level: Preclinical. Evidence comes from animal or lab studies; effects in people are not established. These are areas studied or reported, not promised effects.
Reported side effects and risks
- The naming confusion is itself a safety issue. "CJC-1295" is used in grey markets for both the DAC and non-DAC versions, which have very different durations; a person may not know which they have.
- There are no controlled human trials of Mod GRF 1-29 for body composition or performance, and no regulator has approved it.
- Raising the growth hormone and IGF-1 axis can worsen insulin resistance and raise blood glucose.
- Sustained IGF-1 elevation raises theoretical concern about promoting growth of existing occult malignancy.
- Growth hormone secretagogues are prohibited at all times under the WADA Prohibited List.
- Material sold under this name is research chemical supply with unverified identity, purity, sterility and dose accuracy.
Sources
- PubMed research on GHRH 1-29 modified growth hormone releasing · NIH · National Library of Medicine
- DrugBank record for sermorelin · DrugBank
- Active clinical trials for sermorelin · U.S. National Library of Medicine
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Mod GRF 1-29 FAQ
What is Mod GRF 1-29?
Mod GRF 1-29 is a modified fragment of growth hormone releasing hormone comprising its first 29 amino acids with four substitutions for stability. It is frequently confused with CJC-1295, which is the same peptide with a drug affinity complex attached. It is not approved for human use.
How does Mod GRF 1-29 work?
GHRH(1-29) retains the full biological activity of the 44-amino-acid parent hormone. Four amino acid substitutions resist enzymatic degradation, chiefly by dipeptidyl peptidase-4. It binds the GHRH receptor on pituitary somatotrophs to stimulate growth hormone synthesis and release. Critically, without the DAC modification it does not bind albumin, so its action is short — producing a pulse rather than the sustained elevation ("bleed") of CJC-1295 with DAC.
Is Mod GRF 1-29 FDA approved?
No. Mod GRF 1-29 is a research compound and not approved by the FDA for human use. Evidence level: preclinical. Evidence comes from animal or lab studies; effects in people are not established.
What is the half-life of Mod GRF 1-29?
Reported half-life: Roughly 30 minutes, in contrast to the multi-day half-life of the DAC-modified version.
How is Mod GRF 1-29 taken?
Subcutaneous injection in non-clinical use.
What side effects have been reported with Mod GRF 1-29?
Reported in the sources: The naming confusion is itself a safety issue. "CJC-1295" is used in grey markets for both the DAC and non-DAC versions, which have very different durations; a person may not know which they have; There are no controlled human trials of Mod GRF 1-29 for body composition or performance, and no regulator has approved it; Raising the growth hormone and IGF-1 axis can worsen insulin resistance and raise blood glucose; Sustained IGF-1 elevation raises theoretical concern about promoting growth of existing occult malignancy; Growth hormone secretagogues are prohibited at all times under the WADA Prohibited List; Material sold under this name is research chemical supply with unverified identity, purity, sterility and dose accuracy.
Educational summary compiled from the sources listed above. Not medical advice. Peptide Vault does not sell, source or recommend any compound. Talk to a qualified clinician before starting or changing anything.