GH Optimization Stack (CJC-1295 + Ipamorelin)

Status of research: September 2026 · all sources with PubMed reference

What's included in the set

Both peptides are filled separately and are reconstituted separately. The set is an assembly of individual substances, not a premixed preparation.

Why this combination is pharmacologically justified

The somatotropic axis has two inputs. One is the hypothalamic growth hormone-releasing hormone, which triggers the cAMP cascade at its own receptor. The other is the ghrelin receptor GHS-R1a, whose activation proceeds via protein kinase C and calcium and which additionally attenuates the somatostatin brake. Two different receptors, two different signaling pathways, one shared endpoint — exactly the constellation in which more than mere addition becomes possible.

Unlike most peptide combinations sold commercially, this point is documentedfor the substance classes: the combined administration of a GHRH analog and a ghrelin receptor agonist produces a stronger GH response in the literature than the individual substances alone would suggest. Raun et al. (1998, European Journal of Endocrinology) described this in the initial characterization of Ipamorelin based on the pharmacological profile with GHRP and GHRH antagonists. For the GHRH analog contained here, it additionally holds true what Ionescu and Frohman (2006) showed for the albumin-bound variant: the pulsatile structure of GH secretion is preserved, because the hypothalamus continues to dictate the timing via somatostatin.

Important for context: for this specific two-substance combination in this quantity ratio, there is no dedicated published study. What is documented is the principle, not the product.

CJC-1295 without DAC: the first component

The molecule is a modified analog of the first 29 amino acids of GHRH — the segment that carries full activity and, as a drug substance, bears the generic name sermorelin. The modifications protect against degradation by dipeptidyl peptidase 4. Jetté et al. (2005, Endocrinology) synthesized the underlying derivatives, coupled them ex vivo to serum albumin, and demonstrated both the increased protease stability and the unchanged activation of the GRF receptor at the pituitary.

The clinical data for the substance family — Teichman et al. (2006) with two randomized, placebo-controlled double-blind studies over 28 and 49 days, as well as Sackmann-Sala et al. (2009) on the serum protein profile — relate to the albumin-coupled variant with a half-life of around eight days. The form contained here, without an albumin anchor, acts within a short time window; this distinction is critical for any sampling schedule. Memdouh et al. (2021) also distinguish between the two forms analytically. The full account is available on the product page.

Ipamorelin: the second component

Ipamorelin is the pentapeptide Aib-His-D-2-Nal-D-Phe-Lys-NH₂ and was described by Raun et al. (1998) as the first selective growth hormone secretagogue . It releases GH with a potency and strength comparable to GHRP-6 , without its accompanying effects on ACTH, cortisol, and prolactin — the reason it is regarded in research as the clean tool of this class.

The receptor had already been cloned by the time of this work (Howard et al., 1996, Science), its natural ligand ghrelin followed shortly after (Kojima et al., 1999, Nature); Davenport et al. (2005) and Gnanapavan et al. (2002) described nomenclature and tissue distribution. Pharmacokinetics and pharmacodynamics in humans were investigated by Gobburu et al. (1999); further work concerns the GH response in animals (Johansen et al., 1999; Svensson et al., 2000), pituitary morphology (Jiménez-Reina et al., 2002), and gastrointestinal motility (Venkova et al., 2009). The full account is available on the Ipamorelin product page.

What the combination means in the experiment

Because both substances act on different receptors, simultaneous administration produces a different GH curve than either alone — higher at the peak and usually steeper in its rise. For the analysis of the experiment, it follows that the peak value alone is not sufficient: only the area under the curve over a sufficiently long window describes the actual release, and only the pulse structure shows whether the physiological timing is preserved.

A second point concerns the order. Whether both substances are given simultaneously or with a time offset changes the outcome, because the somatostatin inhibition caused by the ghrelin receptor agonist opens a time window in which the GHRH analog acts more strongly. Timing offset is therefore its own experimental variable and not a side issue.

Why pulsatility is the real point

Growth hormone is not released evenly but in bursts, generated by an interplay of releasing hormone and inhibitory somatostatin. This timing is not a side property: target tissues distinguish between pulsatile and continuous exposure, and downstream gene expression, at the same total amount, differs depending on whether it arrives in bursts or evenly.

This is exactly where the methodological difference lies between a secretagogue approach and direct administration of growth hormone. A secretagogue can only release what the pituitary provides, and in doing so it remains embedded in the feedback system: if downstream IGF-1 rises, it dampens further release. Direct hormone administration bypasses this regulation entirely. For research, the secretagogue approach is therefore the right tool when the regulation of the axis is to be investigated, and the wrong tool when a defined, constant hormone concentration is needed.

For the analysis, a concrete requirement follows from this: a single measurement at a fixed time does not describe a pulsatile response. What is needed is a series of measurements across the entire response window, the area under the curve as the primary metric, and, where possible, a deconvolution analysis that separates the number, height, and width of the individual bursts. Only this makes it visible whether a combination amplifies, prolongs, or merely shifts the bursts — three outcomes that can look identical in a single measurement.

For experimental design

• Four arms. Control, GHRH analog alone, Ipamorelin alone, combination — without the individual arms, synergy cannot be distinguished from simple addition.
• Dense sampling grid. Without an albumin anchor, the GHRH analog acts briefly; GH measurements need intervals of minutes, not hours.
• Control somatostatin tone. Anesthesia, time of day, feeding state, and glucose load systematically alter the response and must be held constant across all arms.
• Measure selectivity as well. Cortisol and prolactin belong in the protocol — they are the litmus test for the selectivity of the ghrelin receptor agonist and the benchmark against non-selective secretagogues.
• Record IGF-1 as a downstream endpoint. GH peaks are short-lived; the effect on the axis only becomes visible in the downstream growth factor and its binding protein.
• Systematically test timing offset. Treat simultaneous and offset administration as separate experimental conditions, not mixed together.

Separate vials or a combination vial?

The same axis can also be addressed with a jointly filled vial . The choice between the two formats is not a matter of preference but follows from the experimental objective.

Separate vials are mandatory as soon as the ratio between the two substances is to be investigated. Only this way can individual arms be run, dose-response curves recorded separately, and the timing offset between administrations varied — and precisely this timing offset is, for two substances that mutually open each other's window of action, one of the most interesting variables.

A fixed combination vial shows its strength once the ratio is already established on solid grounds and many similar batches follow: fewer pipetting steps, fewer transfer errors, less substance loss through dead volume. It does, however, presuppose that the justification for the ratio comes from an experiment with separated substances.

The sensible order is therefore: first test separately, determine the ratio, then combine it fixed for routine use. Anyone who starts with the combination vial saves work but loses the ability to ever determine the contribution of each individual component.

Research applications

Sets of this composition are used in biomedical research in various contexts: (1) investigation of the synergy between GHRH and ghrelin receptor signaling pathways; (2) GH release assays on pituitary cell cultures; (3) pulsatility analyses of GH secretion; (4) selectivity comparisons against non-selective secretagogues; (5) GH-IGF-1 axis models; (6) timing offset studies on somatostatin interaction; (7) receptor binding and desensitization studies; (8) analytical method development for the simultaneous determination of two peptides.

Reconstitution and Yield

The information given applies exclusively to laboratory practice, not to any use in humans or animals.

For converting concentration, volume, and scale value, the Calculator is available; a suitable solvent is bacteriostatic water for multiple withdrawals. The current price is shown in the purchase box at the top of this page.

Quality: why every batch must be individually documented

For both peptides, the same applies as for the individual products: HPLC purity of at least 99% and identity confirmed by mass spectrometry with its own batch number and its own certificate of analysis. For the 29-mer peptide, deletion sequences are the typical impurity, because coupling losses multiply over the chain length; the mass at the same time confirms that the modifications are present — an unmodified GRF(1-29) would be degraded within minutes in an experiment. For the pentapeptide, epimers at the D-amino acids are the critical point: same mass, different retention time, altered receptor binding. For quantitative work, net peptide content is added for both.

Every ALPHASYNTH batch is tested by HPLC for purity and by Mass spectrometry for identity. The Certificate of Analysis (COA) is linked to the order and can be retrieved via the Vial Check using the batch designation; an overview of all reports is available at Lab Reports. How to read a COA is explained in the article How to read a Certificate of Analysis.

Specifications

Storage & Shelf Life

Laboratory Procedure

1. Bring all components to room temperature.
2. Disinfect the septa of the peptide vials and the solvent container and allow to dry.
3. Using a fresh syringe, draw up the solvent and add it slowly along the inner wall of the first vial.
4. Swirl gently until fully dissolved; do not shake. Visually inspect for clarity.
5. Use a fresh syringe for the second peptide.
6. Label both vials with concentration and date, store refrigerated and protected from light.
7. In the experiment, combine the portions only in the preparation itself and record the timing offset.

Shipping & Handling

• Shipped by DHL from Germany, delivery within Germany typically 1–3 business days, within the EU 3–5 business days
• Discreet shipping, no product name on the package
• Lyophilizates are stable for transport for 2–3 days at room temperature; after receipt, store refrigerated or frozen
• Batch number on every vial, Certificate of Analysis (COA) available per batch

Related pages

• CJC-1295 without DAC · Ipamorelin — the individual substances with the full evidence base
• CJC-1295 with Ipamorelin in a combination vial — the same axis in a different format
• CJC-1295 with DAC — the albumin-coupled variant with the clinical data
• GHRP-6 · GHRP-2 · Hexarelin — the non-selective secretagogues for comparison