Growth & GH-Axis — 13 Compounds Compared

What this category covers

The growth and GH-axis category covers GHRH analogs, ghrelin-mimetic growth-hormone secretagogues, and IGF-1 variants — compounds that sit at three different points on the same axis rather than three versions of one idea.

GHRH analogs act at the GHRH receptor on the pituitary. Growth-hormone secretagogues act at a different receptor entirely, the ghrelin receptor. IGF-1 analogs act downstream of growth hormone altogether. A finding about one group is not transferable to another, which is the most common misreading in this literature and the reason the mechanism groups below are set out explicitly.

Within the GHRH group the meaningful variable is duration. The same receptor, stimulated in short pulses or continuously, does not produce the same downstream result — the qualifier in each entry's compound class (short-acting, long-acting, with or without a drug-affinity complex) is carrying real information, not marketing.

Every entry in this category, side by side

All 13 compounds PeptiDex documents under Growth & GH-Axis, on the specifications that actually separate one entry from another. Values are reproduced from each entry's own record; follow any name for the full research overview.

Every Growth & GH-Axis entry in the PeptiDex library, compared on compound class, residue count, molecular weight and reported half-life.
Entry	Compound class	Length (aa)	Molecular weight	Reported half-life
Ipamorelin	Growth-hormone secretagogue (GHRP) / ghrelin receptor agonist	5	711.9 g/mol	~2 hours (reported approximately 120 minutes)
Sermorelin	GHRH analog (growth-hormone-releasing hormone analog)	29	3357.9 g/mol	Short, on the order of minutes (reported approximately 10-20 minutes)
CJC-1295	GHRH analog (long-acting, with Drug Affinity Complex / DAC)	30	Approximately 3647 g/mol (with DAC linker)	Substantially extended vs native GHRH; reported on the order of days (approximately 6-8 days) due to albumin binding via DAC
MK-677 (Ibutamoren)	Orally active non-peptide growth-hormone secretagogue (ghrelin-receptor agonist)	Not listed	624.8 g/mol (free base); approximately 936.2 g/mol as the mesylate salt	Approximately 24 hours (supports once-daily dosing in studies)
Hexarelin	Growth-hormone secretagogue (GHRP) / ghrelin receptor agonist	6	887.0 g/mol	Short, on the order of tens of minutes (reported approximately 55 minutes)
GHRP-2	Growth-hormone secretagogue (GHRP) / ghrelin receptor agonist	6	817.0 g/mol	Short, on the order of tens of minutes (reported approximately 30-60 minutes)
GHRP-6	Growth-hormone secretagogue (GHRP) / ghrelin receptor agonist	6	873.0 g/mol	Short, on the order of tens of minutes (reported approximately 15-60 minutes)
IGF-1 DES	IGF-1 analog (truncated des(1-3) IGF-1 variant)	67	Approximately 7372 g/mol	Very short in circulation (minutes), reflecting IGF-1's rapid clearance when not bound to IGFBPs
IGF-1 LR3	IGF-1 analog (Long R3 IGF-1 variant)	83	Approximately 9111 g/mol	Substantially longer than native IGF-1; reported on the order of many hours (approximately 20-30 hours) due to reduced IGFBP binding
Tesamorelin	GHRH analog (stabilized long-acting GHRH(1-44) analog)	44	Approximately 5136 g/mol	Short in circulation (reported approximately 26-38 minutes) despite chronic dosing effects
CJC-1295 + Ipamorelin Blend	Combination product: GHRH analog (CJC-1295) + GHRP/ghrelin-receptor agonist (ipamorelin)	Not listed	Not listed	Not listed
CJC-1295 (No DAC)	GHRH analog (short-acting modified GHRH(1-29), aka Mod GRF 1-29)	29	Approximately 3368 g/mol	Short, on the order of tens of minutes (reported approximately 30 minutes), longer than native GHRH but far shorter than the DAC version
PEG-MGF	IGF-1 splice variant analog (PEGylated Mechano Growth Factor)	24	~2867 Da (peptide core, excluding PEG)	Extended relative to unmodified MGF due to PEGylation (reported on the order of days), though precise values are not well established

Of the 13 compounds above, 12 carry a published molecular weight, 12 have a reported half-life, 11 have a documented residue count and 8 have a published amino-acid sequence. No half-life is recorded for CJC-1295 + Ipamorelin Blend.

A cell reading "Not listed" is a gap in the published record, not an omission on this page. PeptiDex records a specification only where a source documents it. Some entries here are blends or multi-component preparations, which have no single molecular weight to report at all. Where a value has never been established in the published literature the cell says so, rather than carrying an estimate — a plausible-looking number would make the table read as complete while making it wrong.

Mechanisms represented in this category

The 13 compounds here resolve into 6 compound classes, 3 of which are shared by more than one entry. Entries inside a group carry the same stated class; entries in different groups are not interchangeable, however similar their research context looks.

GHRH analog 4 entries

Sermorelin — Sermorelin is an agonist of the GHRH receptor on anterior-pituitary somatotrophs, stimulating the synthesis and pulsatile secretion of endogenous growth hormone.
CJC-1295 — CJC-1295 is a GHRH-receptor agonist that stimulates pulsatile GH secretion from the pituitary.
Tesamorelin — Tesamorelin is an agonist of the GHRH receptor on anterior-pituitary somatotrophs, stimulating endogenous GH secretion and raising IGF-1.
CJC-1295 (No DAC) — This peptide is a GHRH-receptor agonist that stimulates pulsatile GH release from the pituitary.

Growth-hormone secretagogue / ghrelin receptor agonist 4 entries

Ipamorelin — Ipamorelin is an agonist of the growth-hormone secretagogue receptor (GHS-R1a, the ghrelin receptor), mimicking ghrelin to stimulate GH release from the anterior pituitary.
Hexarelin — Hexarelin is an agonist of the growth-hormone secretagogue receptor (GHS-R1a, ghrelin receptor), stimulating GH release from the pituitary.
GHRP-2 — GHRP-2 is an agonist of the growth-hormone secretagogue receptor (GHS-R1a, ghrelin receptor), stimulating pulsatile GH release from the pituitary.
GHRP-6 — GHRP-6 is an agonist of the growth-hormone secretagogue receptor (GHS-R1a, ghrelin receptor), stimulating pulsatile GH release from the pituitary.

IGF-1 analog 2 entries

IGF-1 DES — IGF-1 DES is an agonist of the IGF-1 receptor, activating the same anabolic and proliferative signaling as native IGF-1.
IGF-1 LR3 — IGF-1 LR3 is an agonist of the IGF-1 receptor, driving the same anabolic and proliferative signaling as native IGF-1.

Combination product: GHRH analog + GHRP/ghrelin-receptor agonist

CJC-1295 + Ipamorelin Blend — The blend pairs two distinct mechanisms: CJC-1295 agonizes the GHRH receptor while ipamorelin agonizes the growth-hormone secretagogue (ghrelin) receptor.

IGF-1 splice variant analog

PEG-MGF — MGF is a splice variant of IGF-1 whose distinctive C-terminal E-domain is implicated in activating muscle satellite (stem) cells and promoting local muscle repair and hypertrophy after mechanical stress, with actions that appear partly independent of the classical IGF-1 receptor.

Orally active non-peptide growth-hormone secretagogue

MK-677 (Ibutamoren) — MK-677 is an agonist of the growth-hormone secretagogue receptor (GHS-R1a, the ghrelin receptor), mimicking ghrelin to stimulate pulsatile GH release from the pituitary and raise circulating IGF-1.

Each line is the opening sentence of that entry's own mechanism record, reproduced verbatim. The full mechanism, the research areas behind it and the evidence level sit on the entry's page.

How the compounds in this category differ

Sharing a category does not make two compounds substitutes. Each note below is the differentiator recorded on that entry — the property that separates it from the others in the table.

Ipamorelin

A selective GH-secretagogue peptide studied in pulsatile GH-release research.

Among GHRPs, ipamorelin is noted for its selectivity — stimulating GH release without the appetite, cortisol, and prolactin elevations associated with GHRP-6 and hexarelin.

Sermorelin

A 29-amino-acid analog of GHRH used in growth-axis research.

Sermorelin is a GHRH-receptor agonist (GHRH 1-29) rather than a ghrelin-receptor GHRP, and it is shorter-acting than modified GHRH analogs such as CJC-1295 or tesamorelin.

CJC-1295

A long-acting GHRH analog often referenced alongside Ipamorelin in research literature.

The DAC version's albumin binding gives it a far longer half-life (days) than the no-DAC 'Mod GRF 1-29' (minutes), making it the long-acting member of the CJC-1295 family.

MK-677 (Ibutamoren)

An orally active ghrelin-receptor agonist studied in GH-axis research.

Unlike the peptide secretagogues in this class, MK-677 is a non-peptide, orally active, long-acting ghrelin-receptor agonist, making its route and pharmacokinetics fundamentally different.

Hexarelin

A synthetic hexapeptide studied in growth-hormone secretagogue research.

Hexarelin is among the most potent GHRPs and uniquely binds CD36 (of cardiovascular interest), but it is less selective than ipamorelin and shows notable receptor desensitization.

GHRP-2

A synthetic GH-releasing peptide studied alongside GHRH analogs.

GHRP-2 is a potent GH releaser with an approved diagnostic use in Japan (pralmorelin), and it stimulates appetite, distinguishing it from the more selective ipamorelin.

GHRP-6

An early-generation GH-releasing peptide referenced in foundational research.

GHRP-6 is historically foundational and produces the strongest appetite stimulation among common GHRPs, but is less selective (more cortisol/prolactin) than ipamorelin.

IGF-1 DES

A truncated analog of insulin-like growth factor-1 studied in localized growth-factor research.

IGF-1 DES differs from native and LR3 IGF-1 by its N-terminal truncation (des 1-3), which lowers IGFBP binding and increases local potency but with a short systemic half-life, unlike the long-acting LR3 variant.

IGF-1 LR3

A long-acting analog of insulin-like growth factor-1 studied in IGF-axis research.

IGF-1 LR3 is engineered for a long half-life via Arg3 substitution and an N-terminal extension that minimize IGFBP binding, contrasting with the short-acting, truncated IGF-1 DES.

Tesamorelin

A synthetic GHRH analog studied in growth-hormone and metabolic research.

Tesamorelin is a stabilized GHRH(1-44) analog and, uniquely in this set, an FDA-approved medicine, distinguishing it from research-only GHRH analogs like sermorelin and CJC-1295.

CJC-1295 + Ipamorelin Blend

A research-supplier blend combining the GHRH analog CJC-1295 with the GH-secretagogue Ipamorelin, often paired in growth-axis research.

Unlike single-agent GHRH analogs or GHRPs, this is a combination formulation designed to engage both the GHRH and ghrelin receptor pathways simultaneously.

CJC-1295 (No DAC)

A short-acting form of CJC-1295 lacking the Drug Affinity Complex, referenced in pulsatile GH-release research.

The absence of the DAC albumin-binding group makes this a short-acting, pulse-generating GHRH analog, in direct contrast to the long-acting DAC version of CJC-1295.

PEG-MGF

A PEGylated form of mechano growth factor referenced in muscle and tissue-repair research.

PEG-MGF is based on a mechanically induced IGF-1 splice variant (MGF) rather than mature IGF-1, and PEGylation gives it a long half-life while the peptide's focus is local muscle repair via satellite cells.

Commonly co-studied pairs

Pairings documented on the entries themselves, with the reason each is co-referenced. Cross-referencing research context is not a combination recommendation, and PeptiDex gives no protocol, ratio or dosing guidance.

Within Growth & GH-Axis

Ipamorelin + CJC-1295 — GHRH analog + GHRP combination is studied for synergistic amplification of GH pulses.
Ipamorelin + CJC-1295 (No DAC) — Short-acting GHRH analog co-studied with ipamorelin to mimic natural pulsatile GH release.
Ipamorelin + Sermorelin — GHRH analog paired with ipamorelin's GHS-R agonism in dual-pathway GH-release research.
Sermorelin + GHRP-2 — Co-studied to combine GHRH-receptor and ghrelin-receptor stimulation for amplified GH pulses.
CJC-1295 + GHRP-2 — Co-studied to pair sustained GHRH tone with potent ghrelin-receptor GH stimulation.
CJC-1295 + CJC-1295 + Ipamorelin Blend — Pre-combined blend formalizes the GHRH + GHRP research pairing in a single vial.
MK-677 (Ibutamoren) + CJC-1295 — Oral ghrelin mimetic co-studied with a GHRH analog to combine ghrelin and GHRH pathways.
MK-677 (Ibutamoren) + Ipamorelin — Both are GHS-R agonists; studied together (or compared) in GH-secretagogue research.

16 further pairings are documented on the individual entries. Each note is reproduced from the entry that records the pairing.

What this category is studied for

Research areas drawn from the 13 compounds in this category, deduplicated and ordered by how many entries list them. A further 38 research areas are listed across the individual entries.

Listing a research area records where a compound has been studied. It is not a claim of efficacy, an indication, or a suggestion of human use.

Category questions

How many compounds does PeptiDex list under Growth & GH-Axis?

13: Ipamorelin, Sermorelin, CJC-1295, MK-677 (Ibutamoren), Hexarelin, GHRP-2, GHRP-6, IGF-1 DES, IGF-1 LR3, Tesamorelin, CJC-1295 + Ipamorelin Blend, CJC-1295 (No DAC) and PEG-MGF. Each has its own research overview covering compound class, mechanism, studied research areas, specifications and entry-specific questions.

Why do some entries show "Not listed" instead of a molecular weight or half-life?

Because PeptiDex records a specification only where a source documents it. In this category 12 of 13 entries have a published molecular weight and 12 have a reported half-life. Some entries here are blends or multi-component preparations, which have no single molecular weight to report; for the rest, the value has simply not been established in the published literature. An estimate there would look like data and function as a guess, so the gap is shown instead.

What compound classes are represented in this category?

6 distinct classes across the 13 compounds: Growth-hormone secretagogue / ghrelin receptor agonist, GHRH analog, Orally active non-peptide growth-hormone secretagogue, IGF-1 analog, Combination product: GHRH analog + GHRP/ghrelin-receptor agonist and IGF-1 splice variant analog. Entries sharing a class are grouped together in the mechanisms section; the comparison table lists each entry's full class verbatim, qualifiers included.

Which entries in this category are studied together?

Ipamorelin and CJC-1295 are cross-referenced on each other's entries: GHRH analog + GHRP combination is studied for synergistic amplification of GH pulses. The co-studied pairs section lists the rest. Co-reference describes how the literature groups compounds; it is not a combination recommendation and no ratios or protocols are given.

Are the compounds in this category approved for human use?

PeptiDex documents all 13 entries strictly for research and educational purposes and provides no dosing, protocol or human-use guidance. Regulatory status differs from entry to entry and is stated in the regulatory note on each entry's own page. Nothing here is medical advice or a therapeutic claim.

Where should I start in this category?

The comparison table gives the fastest orientation, then the differentiator notes explain why two entries with similar research contexts are not interchangeable. Ipamorelin is the entry PeptiDex features here. The glossary defines the vocabulary the entries are written in.

Answers summarise what the catalog records for this category. They are educational context, not medical advice. See the Research Library, the Glossary and each entry's own page for detail.