Sermorelin vs CJC-1295
Bottom line
Both are GHRH analogs — they prompt the pituitary to release the body’s own growth hormone rather than supplying GH directly, so both belong to the Growth Hormone Secretagogues class. Sermorelin is a short-acting, historically FDA-approved GHRH(1-29) peptide now sold as a compounded prescription; CJC-1295 is a chemically stabilized GHRH analog that comes in a long-acting “DAC” form and a short-acting “no-DAC” form (Mod GRF 1-29), is not FDA-approved, and its drug development was discontinued. The practical difference is duration of action and regulatory standing.
At a glance
| Sermorelin | CJC-1295 | |
|---|---|---|
| What it is | GHRH(1-29) amide — the native active fragment | Modified GHRH(1-29) with 4 stabilizing substitutions; ± a DAC albumin-binding linker |
| Mechanism | GHRH-receptor agonist (endogenous GH → IGF-1) | GHRH-receptor agonist (endogenous GH → IGF-1) |
| Half-life | ~10–20 min (short, pulsatile) | DAC: ~6–8 days · no-DAC (Mod GRF 1-29): ~30 min |
| Typical dosing | ~100–300 µg SC once daily (bedtime) | DAC ~1–2 mg/week · no-DAC ~100 µg, 1–3×/day |
| Evidence level | Clinical (historical approved drug; modern uses extrapolated) | Clinical for raising GH/IGF-1 (PK studies only); no efficacy RCTs |
| FDA / legal status | Formerly approved (Geref, 1997; withdrawn 2008–09, not for safety); now compounded prescription | Not approved; development discontinued; sold as a research chemical |
| Route | Subcutaneous | Subcutaneous (or IM) |
Key Differences
- Duration of action. Sermorelin is short-acting (~10–20 min), producing a brief, physiologic GH pulse — the rationale for once-daily bedtime dosing. CJC-1295 exists in two very different forms: the DAC version binds albumin for a ~6–8 day half-life (sustained GH/IGF-1, weekly dosing), while the no-DAC version (Mod GRF 1-29) acts for ~30 minutes like sermorelin. Despite the shared “CJC-1295” name, the DAC and no-DAC forms are pharmacologically distinct.
- Pulsatile vs sustained. Sermorelin and no-DAC CJC-1295 preserve a more pulsatile GH pattern; DAC CJC-1295 produces a sustained (“bleed”) elevation that some researchers consider less physiologic.
- Regulatory standing — the decisive gap. Sermorelin has a real approval history (Geref, 1997) and is legally dispensed today as a compounded prescription. CJC-1295 was never approved, its clinical development was halted, and any product sold now is gray-market research material of uncertain identity/purity (the DAC vs no-DAC label is frequently mislabeled).
- Evidence base. Sermorelin’s human history includes an approved pediatric/diagnostic indication, though its modern adult “wellness” uses are extrapolated. CJC-1295’s human data is limited to early-phase PK studies (e.g., Teichman 2006) showing it raises GH and IGF-1 — there are no trials demonstrating muscle, fat-loss, or performance benefits.
- How they’re used. Both are commonly paired with a GHRP/ghrelin mimetic like Ipamorelin to amplify a GH pulse (see CJC-1295 + Ipamorelin); sermorelin follows the same logic. Sermorelin is often positioned as an “entry-level” GH peptide in wellness clinics.
Which Is Which
- A legally prescribable option points to sermorelin (via a compounding pharmacy, under a clinician) — it has the regulatory history and a defined dosing record.
- The “long-acting” peptide people ask about is CJC-1295 with DAC (weekly dosing) — but it is unapproved, lacks efficacy trials, and carries the sourcing risks of any research chemical.
- “Mod GRF 1-29” is simply CJC-1295 without DAC — short-acting, dosed multiple times daily, usually with a GHRP.
- Both are GH secretagogues prohibited in and out of competition under the WADA Prohibited List (Section S2). Neither builds GH directly; both depend on a functioning pituitary. See Regulatory & Legal Status and Evidence Grading Explained.
Not medical advice — See Disclaimer.
References
- Walker R.F. (2006). “Sermorelin: a better approach to management of adult-onset growth hormone insufficiency?” Clinical Interventions in Aging.
- U.S. FDA / Federal Register (2013). Determination that GEREF (sermorelin acetate) was not withdrawn for reasons of safety or effectiveness.
- Teichman S.L. et al. (2006). “Prolonged stimulation of GH and IGF-I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults.” J Clin Endocrinol Metab, 91(3):799–805.
- Ionescu M., Frohman L.A. (2006). “Pulsatile secretion of GH persists during continuous stimulation by CJC-1295.” J Clin Endocrinol Metab, 91(12):4792–4797.
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