Ipamorelin 2mg

Product status information

Chemical reagent intended exclusively for laboratory tests (Research Use Only). It is not a medicinal product, dietary supplement or food. It is not intended for use on humans or animals. Sales only to registered research units and laboratories.

Regulatory framework – growth hormone secretagogue, Endogenic line

Ipamorelin 2 mg is single-component research reagent in the form of a lyophilisate in a vial – a selective pentapeptide from the class of growth hormone releasing peptides (GHRP), a ghrelin mimetic and a GHS-R1a receptor agonist. Belongs to the line Endogenic Pro-Body, which groups molecular tools that stimulate own the body’s secretory axes, instead of providing exogenous hormone. Ipamorelin is not registered as a medicinal product in any jurisdiction (Novo Nordisk ran a drug development program, the project was abandoned).

The molecule belongs to the class of growth hormone secretagogues, which WADA lists in Section S2 of the Prohibited List. (peptide hormones, growth factors and mimetics) – permanently prohibited substances, both in and outside competitions. Communication suggesting use in humans to increase growth hormone, IGF-1 levels, accelerate regeneration or change body composition is contrary to the Research Use Only framework and is unacceptable.

The secretion of growth hormone is not a flat, steady stream – the pituitary gland releases GH impulses, in pulses of a specific amplitude and frequency, regulated by a pair of opposing signals from the hypothalamus. On the one hand, GHRH (growth hormone releasing hormone) tells the pituitary to “release”, on the other hand, somatostatin says “hold”.

Superimposed on this system is a third player – ghrelin and its receptor (GHS-R1a) – which acts as a separate, complementary switch for GH release. Ipamorelin grows exactly from this third arm: it is a synthetic ghrelin mimetic, a tool for studying what happens when the GHS-R1a receptor is stimulated selectively, without simultaneously triggering the stress axis.

This distinction defines the line Endogenic in the Pro-Body catalogue. Unlike exogenous, recombinant growth hormone, which floods the circulation with a flat, nonphysiological concentration, secretagogues stimulate own pituitary to release GH in a way that preserves the pulsatile signal architecture – involving the somatostatin feedback loop. A whole group of tools of this type, i.e growth hormone-increasing peptides, is based on the same philosophy – modulation of the endogenous secretion rhythm, not the supply of an external hormone.

Ipamorelin is the flagship representative of this research philosophy. This reagent is supplied as 2 mg lyophilisate in a vial, for reconstitution with bacteriostatic water in laboratory conditions.

The freeze-dried form ensures stability of the peptide before dissolution and allows researchers to prepare working concentrations tailored to the experimental design. Purity verified by HPLC ≥98%, identity confirmed by Q-TOF mass spectrometry, COA available for each batch.

To understand where Ipamorelin is located in physiology, you need to see that the pituitary gland receives the “secrete GH” signal through more than one channel. The somatotropic cell of the anterior pituitary has at least two separate receptors on its surface that stimulate the release of growth hormone: GHRH receptor and growth hormone secretion receptor type 1a (GHS-R1a), i.e. ghrelin receptor. These are two different proteins, two different intracellular cascades and two different physiological signals – which converge on the same end result, the release of GH from secretory granules. Ghrelin receptor (GHS-R1a) is a Gq protein-coupled receptor.

Its stimulation activates phospholipase C, increases intracellular calcium and leads to the release of GH – in a way separate from GHRH. Importantly, the ghrelin arm additionally suppresses somatostatin (inhibiting hormone) and enhances its own GHRH action. Physiologically, secretagogues acting on this receptor influence frequency and pulsatility GH release. This is the channel on which Ipamorelin – and the entire class of growth hormone releasing peptides (GHRPs) – are based.

The endogenous ligand of GHS-R1a is ghrelin — a peptide gastrointestinal hormone, known primarily for its role in the regulation of appetite and energy balance, but also acting as a strong physiological secretagogue of GH.

Ghrelin mimetics, such as Ipamorelin, mimic this action at the level of the pituitary receptor, opening the possibility of separating the “GH release” component from the remaining functions of ghrelin (orexigenic, cardiovascular, metabolic) in research. The pulsatile nature of GH secretion is the main physiological detail here. The strongest nocturnal GH pulse occurs during slow-wave sleep, and ghrelin secretagogues modulate the architecture of this signal, preserving its impulsive nature.

This “endogenous, pulsatile” release pattern is the subject of research on the physiology of the GH/IGF-1 axis, sleep regulation, and the differences between secretagogue stimulation and administration of recombinant GH.

The pharmacology of growth hormone secretagogues includes two large classes of tools:

• GHRH analogues — mimic the endogenous GH-releasing hormone, stimulate the GHRH receptor, increase the pulse amplitude (CJC-1295, sermorelin, tesamorelin)
• GH-releasing peptides (GHRP) and ghrelin mimetics — stimulate the GHS-R1a ghrelin receptor, influence the pulse frequency and suppress somatostatin (Ipamorelin, GHRP-2, GHRP-6, hexarelin)

Within the second class, Ipamorelin occupies a special position – it is the most selective of the described GHRPs, which makes it a model tool for studying “pure” stimulation of the GH axis by the ghrelin receptor.

Chemically, Ipamorelin is a synthetic pentapeptide with a C-terminal amide, designed as a selective ghrelin mimetic.

• Common name: Ipamorelin
• Name/sequence: Aib-His-D-2-Nal-D-Phe-Lys-NH₂ (pentapeptide, C-terminal amide; contains the aminoisobutyric acid residue Aib and D-amino acid residues stabilizing the peptide against proteolysis)
• Synonyms: NNC 26-0161, Ipamorelin acetate (acetate salt form)
• CAS number: 170851-70-4
• Molecular formula: C₃₈H₄₉N₉O₅
• Molar mass: 711.85 g/mol
• Chemical class: pentapeptide; selective agonist of growth hormone secretagogue receptor type 1a (GHS-R1a); growth hormone releasing peptide (GHRP)
• Supplied form: lyophilisate 2 mg in a vial, for reconstitution with bacteriostatic water; purity ≥98% HPLC

The action of Ipamorelin is based on selective stimulation of the GHS-R1a ghrelin receptor on somatotroph cells of the pituitary gland. What distinguishes this peptide from other GHRPs lies not in the GH release itself – which all GHRPs induce – but in cleanliness this effect: stimulation of the GH axis without simultaneous activation of the stress axis. Pharmacological profile observed in preclinical models:

1. Selective GHS-R1a receptor agonist → pulsatile GH release. Ipamorelin binds the ghrelin receptor (coupled to the Gq protein) on the somatotropic cell, activates the phospholipase C pathway, increases intracellular calcium and leads to the release of growth hormone from the secretory granules. Stimulation preserves the pulsatile signal architecture – it mimics the endogenous, pulsatile pattern of GH secretion (Raun et al. 1998).
2. The most selective of the described GHRPs – without an increase in cortisol, prolactin and ACTH. This is the defining feature of Ipamorelin. In preclinical models, unlike older GHRPs – especially GHRP-6, and to a lesser extent GHRP-2 – Ipamorelin stimulated GH release without significantly increasing cortisol and prolactin levels, with a limited effect on ACTH release (Raun et al. 1998). Older GHRPs, by triggering GH secretion, also activated the pituitary-adrenal axis – Ipamorelin leaves this axis at rest. This “pure” GH-secretagogic profile makes it the preferred tool in models where disruption of the cortisol axis would be a methodological problem.
3. Minimal appetite stimulation. GHRP-6, as a strong ghrelin mimetic with a clear orexigenic profile, stimulated appetite – reflecting the full spectrum of ghrelin action. Ipamorelin has been demonstrated in preclinical models much weaker effect on appetite, which further separates the “GH release” component from the orexigenic arm of ghrelin signaling. This is another axis of selectivity that distinguishes it from older GHRPs.
4. Somatostatin suppression. In addition to direct stimulation of GHS-R1a, the ghrelin arm abolishes somatostatin inhibition — a hypothalamic hormone that suppresses the somatotropic cell. Removing this brake enhances the response to endogenous GHRH and potentiates pulsatile GH release. This mechanism is the basis for the synergy of GHRP with GHRH analogues.
5. Synergy with GHRH (CJC-1295) – amplitude plus frequency. Because Ipamorelin acts through a receptor and cascade separate from GHRH, simultaneous stimulation of both pathways produces an effect in the models. greater than the sum of each individual’s actions. GHRH (e.g. CJC-1295) increases amplitude GH pulse (Gs/cAMP cascade), Ipamorelin affects frequency and pulsatility and suppresses somatostatin, two complementary arms that enhance each other at the level of a single somatotropic cell. This is the rationale behind the classic research pairs such as GHRH analogue plus ghrelin mimetic.

Pharmacokinetic profile (based on preclinical models):

• Plasma half-life: short, approximately two hours in preclinical models – peptide stabilized by D-amino acid residues and Aib, but still subject to proteolysis
• Receptor mechanism: selective, high affinity for GHS-R1a; no significant activity on cortisol axis receptors
• Metabolism: enzymatic hydrolysis of peptide bonds; the presence of D-amino acid residues slows down the degradation compared to fully L-amino acid peptides
• PK profile in humans: insufficiently characterized; available data come from limited, historical studies in an abandoned drug development program

IMPORTANT DISTINCTION – Ipamorelin compared to GHRP-6 and GHRP-2

“Selectivity”, “pure GH profile” and “no increase in cortisol/prolactin” in the context of this description refer only to mechanisms and endpoints reported in preclinical studies of GH secretagogues (Raun et al. 1998; Smith et al. 1997). The most significant difference between Ipamorelin and older GHRPs is the off-axis-GH profile: GHRP-6 stimulates GH, but strongly increases appetite (orexigenic profile) and may increase cortisol and prolactin; GHRP-2 increases GH very strongly, but also activates the cortisol/prolactin axis to a greater extent than Ipamorelin; Ipamorelin stimulates GH selectively, without any significant effect on the stress axis and with minimal effect on appetite.

This distinction is for reference purposes – it describes molecular profiles in the literature, and is not a guarantee of effect for anyone working with the RUO reagent. This is not to suggest that Ipamorelin can act as a “mild GH booster” or a “regeneration peptide without side effects”. Ipamorelin as a model selective GHRP – reference: In the landscape of growth hormone releasing peptides, Ipamorelin occupies a reference position:

• GHRP-6 — strong but non-selective: stimulates GH, increases appetite (orexigenic), activates the cortisol/prolactin axis. The orexigenic profile of this molecule is described on the card GHRP-6.
• GHRP-2 — the strongest GH releaser from this group, but with a more pronounced effect on the stress axis than Ipamorelin. Details of this molecule can be found in the card GHRP-2.
• Ipamorelin — the most selective: stimulates GH through GHS-R1a without a significant increase in cortisol, prolactin and ACTH and with minimal appetite stimulation. A model compound for testing “pure” GH axis stimulation

Ipamorelin as a selective GHRP is used wherever the subject of research is stimulation of the GH axis by the ghrelin receptor without disruption of the cortisol axis. In in vivo models (pig, rat, mouse) and in vitro models (isolated somatotropic pituitary cells, cell lines expressing GHS-R1a), research is carried out on the mechanism, kinetics and selectivity of GH release. Specific research directions include:

• GHRP receptor selectivity — comparative studies on the selectivity of Ipamorelin towards the ghrelin receptor and limited effect on the cortisol/prolactin/ACTH axis (Ipamorelin vs GHRP-6 vs GHRP-2) in cell preparations and in vivo models; Ipamorelin as a reference “pure” secretagogue
• GHS-R1a receptor pharmacology — concentration-response curves, binding affinity, activation kinetics of the Gq/phospholipase C pathway in cell lines expressing the ghrelin receptor
• GHRH + GHRP synergy — measurements of GH release from isolated pituitary cells when stimulated separately by GHRH, separately by Ipamorelin and both simultaneously; quantitative characterization of the additive vs. synergistic effect with the GHRH analogue CJC-1295
• Somatostatin axis — the role of somatostatin suppression by the ghrelin arm in the potentiation of the GHRH response; studies of the feedback loop regulating the GH pulse
• Pulsatility and architecture of GH secretion — studies of how selective GHRP modifies the amplitude and frequency of GH pulses in animal models; comparison of release pattern with administration of recombinant GH
• Separation of ghrelin functions — Ipamorelin as a tool to separate the GH release component from the orexigenic and metabolic arms of ghrelin signaling in energy balance models

Ipamorelin 2 mg is single-component RUO research reagent from the Endogenic line – lyophilisate in a vial, selective pentapeptide from the class of growth hormone releasing peptides (GHRP), ghrelin mimetic and GHS-R1a receptor agonist (sequence Aib-His-D-2-Nal-D-Phe-Lys-NH₂, CAS 170851-70-4, mass 711.85 g/mol). The defining feature of Ipamorelin is its selectivity: developed by Novo Nordisk as the first selective GH secretagogue, in preclinical models it stimulated the release of growth hormone without a significant increase in cortisol, prolactin and ACTH and with minimal appetite stimulation – unlike the older GHRP-6 (strongly orexigenic) and GHRP-2 (more pronounced effect on the stress axis) (Raun et al. 1998).

Mechanistically, it stimulates the ghrelin receptor (Gq cascade/phospholipase C), suppresses somatostatin and works synergistically with GHRH analogues such as CJC-1295 (amplitude plus GH pulse frequency). Lyophilized form 2 mg in a vial, reconstitution with bacteriostatic water, HPLC purity ≥98%, MS Q-TOF, COA for each batch. Regulatory Status – Research Use Only; lack of registration as a medicine; WADA: section S2, permanently prohibited substances.

1. Raun K, Hansen BS, Johansen NL, Thøgersen H, Madsen K, Ankersen M, Andersen PH (1998). Ipamorelin, the first selective growth hormone secretagogue. PubMed
2. Gobburu JV, Agersø H, Jusko WJ, Ynddal L (1999). Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. PubMed
3. Sigalos JT, Pastuszak AW (2018). The safety and efficacy of growth hormone secretagogues. PubMed
4. Smith RG, Van der Ploeg LH, Howard AD, Feighner SD, Cheng K, Hickey GJ, et al. (1997). Peptidomimetic regulation of growth hormone secretion. PubMed