# Compare GH Secretagogues — getgoodpeptides

> A side-by-side comparison of ipamorelin, CJC-1295, sermorelin, and tesamorelin: receptor class, evidence maturity, regulatory status, WADA classification, and distinguishing features.

The same axis, four different approaches — what separates ipamorelin, CJC-1295, sermorelin, and tesamorelin in mechanism, evidence, and regulatory standing.

## The short version

All four compounds on this desk ultimately target the GH/IGF-1 axis, but they do so through different receptor mechanisms, with different durations of action, and from very different regulatory starting points. Ipamorelin acts on the ghrelin receptor (GHS-R1a). The other three — CJC-1295, sermorelin, and tesamorelin — act on the GHRH receptor. Within the GHRH-receptor group, they differ sharply in structure, half-life, and clinical track record.

The table below maps the key differentiating dimensions. The evidence column reflects what controlled human trials actually show, not what community forums report.

## Side-by-side comparison

| | **Ipamorelin** | **CJC-1295** | **Sermorelin** | **Tesamorelin** |
|---|---|---|---|---|
| **Receptor target** | GHS-R1a (ghrelin receptor) | GHRHR (GHRH receptor) | GHRHR (GHRH receptor) | GHRHR (GHRH receptor) |
| **Structure** | Synthetic pentapeptide (5 AA) | Modified hGRF(1-29) with albumin-binding linker (DAC) or without (no-DAC) | GHRH(1-29) fragment — shortest fully active GHRH fragment | GHRH(1-44) analog with N-terminal DPP-IV protection |
| **Duration of action** | Short (terminal t½ ~2 h in humans) [4] | Long (DAC t½ ~5.8–8.1 days) [11]; short for no-DAC form | Short (~10–20 min IV t½); short-acting SC | Medium-short (requires daily dosing for sustained effect) |
| **Studied for** | Selective GH secretion; postoperative ileus (Phase 2) | Sustained GH/IGF-1 elevation; anti-aging/body composition (investigational) | Pediatric GH deficiency (approved); adult body composition (investigational) | HIV-associated lipodystrophy (approved indication) |
| **Strongest human evidence** | PK/PD characterization (n=8/dose) [4]; Phase 2 RCT missed endpoint [3] | GH/IGF-1 elevation in healthy adults (n=28–89) [11][12] | Pediatric height velocity (multicenter RCT) [16]; GHRH-analog cognitive RCT [13] | Visceral fat reduction in HIV adults (5 RCTs, meta-analysis) [17][19][21] |
| **Evidence maturity** | Early; Phase 2 failed; no Phase 3 | Early; no approval; Phase 2 halted | Historical approval (pediatric); limited adult data | Strongest — Phase 3 trials, FDA-approved (HIV indication) |
| **FDA status** | Not approved; not on 503A compounding list | Not approved; not recommended for 503A | Previously approved (NDA 020443); 503A Category 1 | FDA-approved (NDA 022505) for HIV lipodystrophy only |
| **WADA status** | Prohibited S2 (all times) | Prohibited S2 (all times) | Prohibited S2 (all times) | Prohibited S2 (all times, in- and out-of-competition) |
| **Key caution** | Phase 2 RCT failed; class-level cardiac signal from related GHS-R1a agonist [2]; unknown long-term safety | Discontinued development; immunogenicity cited by FDA; DAC/no-DAC routinely confused | Anti-aging use "not yet ready for prime time" [14]; oral/sublingual forms likely inactive | Approval is HIV-specific; visceral fat reaccumulates on discontinuation [21] |

## What the comparison means

A few patterns emerge from the comparison.

**Tesamorelin stands alone on clinical evidence.** It is the only compound here with completed Phase 3 trials and a current FDA approval. The other three are research-grade compounds. No side-by-side comparison of these four in a single controlled human trial exists.

**Sermorelin has the oldest clinical foundation, but in a different population.** Its former approval was specifically for growth-hormone-deficient children — a condition with measurable GH deficiency. That clinical record does not automatically transfer to adults with normal GH axis function seeking body-composition or anti-aging effects. A 2008 editorial said GH-secretagogue anti-aging use is "not yet ready for prime time" [14], and nothing since has overturned that assessment for any compound on this desk.

**Ipamorelin's selectivity is real, but its clinical efficacy is unproven.** The GH-selectivity finding is the most mechanistically clean result for ipamorelin [6], but the only randomized human efficacy trial failed [3]. The popular CJC-1295-plus-ipamorelin combination has no published controlled human trial at all [7].

**CJC-1295's long duration cuts both ways.** The DAC form's ability to sustain GH and IGF-1 elevation for up to 28 days from a single dose [11] is pharmacologically striking. It also means that any adverse effects — fluid retention, glucose perturbation, IGF-1 elevation — are sustained for the same duration, with no quick offset if something goes wrong.

All four are prohibited in competitive sport. Any interpretation of this desk's content as advice to use any of these compounds in humans is mistaken — it is not.

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An independent literature digest of peer-reviewed research on the GH/IGF-1 axis — organized like a clinician's briefing, not a product catalog.