CJC-1295 / Ipamorelin

These are two different peptides hitting two different steps of the growth hormone cascade, sold together in one compounded vial. CJC-1295 is a synthetic GHRH analog binding GHRH receptors in the pituitary; the version carrying a Drug Affinity Complex linker attaches reversibly to albumin, which stretches its half-life to roughly six to eight days and holds GH and IGF-1 up continuously [1]. Strip the linker off — the form labeled Mod GRF 1-29 — and it lasts about half an hour, so dosing gets timed around meals or training instead.

Ipamorelin is a selective growth hormone secretagogue acting at the ghrelin receptor. Unlike the older releasing peptides it is notably selective for GH, leaving cortisol, prolactin and ACTH largely alone across the animal work and what early human data exist [5]. Pairing a GHRH analog with a ghrelin-receptor agonist is thought to amplify GH pulses beyond what either produces alone, since the two arrive at the same somatotroph cell through separate receptors.

The combination is not FDA-approved. Both are compounded and used off-label, marketed mainly for body composition, recovery and aging. There is no published human trial of the combination at all — what exists is one small human study of CJC-1295 by itself, some human tolerability data for ipamorelin from a gut-motility trial, and review literature about GH-axis peptides generally. Claims about losing fat or gaining muscle in healthy adults rest on physiology rather than on any trial of this stack.

CJC-1295 attaches to the GHRH receptors carried by somatotrophs in the anterior pituitary, driving cAMP-mediated transcription and pulsatile release. The DAC modification tethers the peptide to circulating albumin through a reactive ester, which extends how long it stays around and holds GH and IGF-1 at a steady raised level instead of the pulsing rhythm the body normally runs [1]. Whether that difference matters is a fair question, and one nobody has answered in humans. IGF-1 is the proposed mediator downstream for protein synthesis, fat breakdown and repair.

Ipamorelin stands in for acylated ghrelin at GHSR-1a in pituitary and hypothalamus alike, boosting GH output while largely sparing the stress axis and the prolactin-producing cells [[cite:5],[cite:6]]. Given together, the two act on separate but complementary systems: the GHRH side raises how responsive somatotrophs are, while the ghrelin-mimetic lifts the somatostatin brake, and the combined pulse exceeds the sum. That synergy is well described in preclinical models. Human dose-response data for the stack have not been published.

One trial carries the human evidence for CJC-1295: a phase 2 study from 2006 enrolling 65 healthy adults between 21 and 61. Given repeatedly under the skin at 30 to 120 mcg/kg, the DAC version raised mean GH in proportion to dose and held it there — two- to ten-fold over baseline — and IGF-1 up 55 to 70% at the higher doses, both persisting for the better part of a week from one injection, which the authors put down to the albumin binding [1]. There was no ipamorelin arm, and the trial was never designed to measure anything about body composition.

What human tolerability data exist for ipamorelin come partly from a 2014 proof-of-concept randomized trial in surgical patients, given to speed the return of gut function after bowel resection. Tolerance was good and nothing serious was pinned on the drug — genuine reassurance about safety in a controlled setting [4]. It says nothing about body composition or the GH axis in healthy people, because it was not asking.

Reviews of GH-axis peptides in sports and aesthetic medicine name both of these among the most widely self-administered compounds in the category, while noting that controlled human data on fat loss, muscle growth or recovery in healthy subjects simply do not exist [[cite:2],[cite:3]]. A 2026 review covering more than twenty secretagogues concluded that self-administration has far outrun the trial evidence, and that the claims circulating online are extrapolations from GH physiology rather than measured human endpoints [2]. Grade C for this combination: plausible mechanism, one small pharmacokinetic study of half of it, and no randomized trial of the stack.

Preclinically, ipamorelin stimulates GH reliably without engaging the stress axis. A 2024 ferret study found it and the related secretagogue anamorelin blunting cisplatin-induced weight loss, which is what an anabolic GH and IGF-1 response would predict [5]. That supports the mechanism being real. It does not carry across to efficacy in healthy humans, and should not be read as though it does.

Providers offering the compounded combination usually put both in one vial for subcutaneous injection. One widespread protocol puts 100 mcg of the linker-free CJC-1295 alongside 100 to 200 mcg of ipamorelin, once daily, frequently at bedtime to line up with the overnight GH surge. Where the DAC version is used, frequency drops to once or twice weekly because of the long half-life. Cycles of three to six months with a break afterward are widely described and derive from practice rather than from any controlled trial.

Reconstituted vials need refrigerating, bacteriostatic water is the standard diluent, and injection sites should be rotated between abdomen and thigh. This belongs under a licensed prescriber who is actually monitoring IGF-1, rather than self-managed — the point of the monitoring is to catch excessive exposure before it becomes a problem. No FDA-approved protocol for healthy adults exists, all use is off-label, and compounded material lacks the standardization approved drugs carry.

In the 2006 CJC-1295 trial the complaints that recurred were at the injection site — sore, red, swollen — in about a third of participants, plus some temporary flushing of the face [1]. In the 2014 randomized trial, ipamorelin was tolerated well [4]. The broader concerns that come with raising the GH axis apply here: blood glucose rising, since GH opposes insulin; fluid building up; carpal tunnel symptoms; and the theoretical worry that holding IGF-1 high could feed a tumor nobody has found yet. That last one is shared by everything in this category. No long-term safety data exist in healthy adults.

Because these are compounded rather than approved, purity and potency vary by pharmacy and are not standardized. Contamination, wrong doses and unlabeled additives are real risks from unregulated suppliers rather than hypothetical ones. Anyone going ahead should source through a licensed provider using an accredited compounding pharmacy, and should have IGF-1 measured at baseline and again during treatment. Cancer currently active, diabetes, or any past pituitary tumor all rule these out.