Mod GRF 1-29 vs Sermorelin

Modified GHRH analog; binds GHRH receptors with improved stability to produce physiological GH pulses when combined with a GHRP

Mod-GRF 1-29 (also designated CJC-1293 without DAC, or tetrasubstituted GHRH[1-29]) is a synthetic analogue of the first 29 amino acids of growth hormone-releasing hormone, modified at four positions including substitution of norleucine at position 27 to improve proteolytic stability and extend the effective half-life of native GHRH 1-29, thereby producing more sustained pituitary GH stimulation per dose. Like endogenous GHRH, it acts through GHRH receptors on pituitary somatotrophs to stimulate cAMP-mediated GH synthesis and secretion, and is administered to mimic the hypothalamic pulse signal that drives GH release and downstream IGF-1 axis activity. Modified GHRH 1-29 analogues sharing the core amino acid substitutions of Mod-GRF 1-29, specifically [Nle27]GHRH(1-29)-NH2, have been administered to humans in controlled studies that documented sustained GH and IGF-1 axis effects with endocrine, metabolic, and immune endpoints characterized in age-advanced subjects. Mod-GRF 1-29 has not received FDA approval; the related compound sermorelin (unmodified GHRH 1-29) was previously FDA-approved for pediatric GH deficiency but was withdrawn by its manufacturer, and Mod-GRF 1-29 is an investigational compound not approved for any clinical indication. Naming note — Mod GRF 1-29 vs CJC-1295: the research compound marketplace uses several overlapping names for this compound. "Mod GRF 1-29" and "CJC-1295 without DAC" refer to the same tetrasubstituted GHRH(1-29) peptide. "CJC-1295 with DAC" (or simply "CJC-1295" in most clinical protocol contexts) is a different compound — it includes a Drug Affinity Complex (DAC) linker that enables albumin binding and produces a dramatically extended half-life (~8 days vs ~30 minutes for Mod GRF 1-29). CJC-1295 with DAC is used as an infrequent injection (weekly or biweekly) while Mod GRF 1-29 / CJC-1295 without DAC is used at each injection session, typically immediately before or alongside a GHRP such as ipamorelin to maximally leverage the GH pulse window. Dosage in research protocols: Mod GRF 1-29 is typically used at 100 mcg per injection alongside ipamorelin or another GHRP, administered 2–3 times daily or immediately before sleep to align with natural GH secretion peaks. Subcutaneous injection after reconstitution with bacteriostatic water is the standard route. Provider availability for Mod GRF 1-29 and CJC-1295 compounds is listed in the PeptideBase directory.

Sermorelin is a synthetic analogue of the first 29 amino acids of endogenous growth hormone-releasing hormone (GHRH). It binds to GHRH receptors on pituitary somatotrophs, stimulating pulsatile GH secretion in a physiological pattern that preserves the natural hypothalamic-pituitary feedback axis — contrasting with direct GH administration. Downstream IGF-1 elevation mediates many of its body composition, tissue-repair, and sleep quality effects.

Sermorelin acetate is a synthetic 29-amino-acid peptide (GHRH(1-29)NH2) corresponding to the biologically active N-terminal fragment of endogenous growth hormone-releasing hormone, developed as a prescription pharmaceutical to stimulate endogenous GH secretion from the pituitary gland as a diagnostic and therapeutic agent for GH deficiency. Sermorelin acts on pituitary somatotrophs via GHRH receptors to stimulate pulsatile GH release, preserving the natural feedback regulation of the GH axis — an advantage over direct exogenous GH administration — and multiple randomized controlled trials have established its pharmacokinetic and pharmacodynamic profile in populations with GH insufficiency including post-irradiation hypopituitarism. The compound received FDA approval as Geref (Serono) for diagnosis and treatment of GH deficiency in children; approval was voluntarily withdrawn by the manufacturer in 2008 for commercial rather than safety reasons, leaving the underlying human evidence base intact, and compounded sermorelin has since been widely used off-label in adult anti-aging and hormone optimization practice. Sermorelin is currently available only through compounding pharmacies under prescriber supervision; it is not FDA-approved for any current indication, and its use in adults represents off-label prescribing outside the regulatory framework established by its original pediatric approval. Sermorelin is available through telehealth platforms and hormone optimization clinics across the United States and is dispensed by compounding pharmacies under licensed prescriber supervision. Patients searching for sermorelin providers near them or via telehealth can use the PeptideBase directory to browse verified clinics and telehealth platforms offering sermorelin by location. Sermorelin bodybuilding and anti-aging research contexts have driven its widespread compounded use in adults, though these applications are off-label and outside the original pediatric approval framework. Sermorelin near me: sermorelin is available through licensed anti-aging clinics, hormone health practices, and telehealth platforms that specialize in growth hormone axis support. Because sermorelin requires a prescription, access involves a clinical consultation — many providers now offer this remotely via telehealth, eliminating the need for in-person visits. For those searching for sermorelin providers near them, PeptideBase maintains a directory of verified clinics and telehealth platforms offering sermorelin protocols across the United States. Sermorelin and ipamorelin together: yes, sermorelin and ipamorelin are frequently combined in clinical research and compounded hormone optimization protocols. The two peptides act on different receptors — sermorelin on GHRH receptors (stimulating the GHRH pathway) and ipamorelin on ghrelin receptors (GHS-R1a) — and their mechanisms are complementary rather than redundant. Combining a GHRH analog like sermorelin with a GHRP like ipamorelin produces synergistic GH release, consistent with the well-established pharmacological principle that GHRH and GH secretagogues act additively at the pituitary. Ipamorelin is specifically valued in this combination for its selectivity — it stimulates GH without the cortisol or prolactin co-stimulation that characterizes less selective GHRPs such as GHRP-2 or GHRP-6. The sermorelin + ipamorelin combination (and its extension, the sermorelin + CJC-1295 + ipamorelin triple protocol) is among the most commonly prescribed compounded GH secretagogue regimens in anti-aging and hormone optimization practice. Providers offering combination GH secretagogue protocols are listed in the PeptideBase directory.