Tesamorelin and CJC-1295: same receptor, different molecules
What the published record says about tesamorelin, CJC-1295 and ipamorelin: the receptor each binds, the half-life figures, and what the searches found.
Research use only. This page provides scientific background and community-report context. Every compound sold here is supplied strictly for in-vitro research. Nothing on this page is a protocol, a recommendation or medical advice.
TL;DR: receptor identity and the evidence map
Research question: Do the published studies test tesamorelin together with a second GHRH analogue or with a GHRP?
What the published data say: Tesamorelin and CJC-1295 belong to the GHRH receptor story; ipamorelin belongs to the GHRP receptor story. Receptor identity alone does not establish a clinical combination outcome. [EGRIFTA SV PI 12.1; PMID 15817669; PMID 9849822]
What has not been studied: PubMed search tesamorelin AND (ipamorelin OR "CJC-1295" OR sermorelin) AND ("clinical trial"[pt] OR "randomized controlled trial"[pt]), dated 2026-09-13, returned 0 records: no human trial of tesamorelin with a second GHRH analogue was identified.
What research communities report: In the Reddit corpus we track, 157 question posts in 12 months matched the named-compound combination patterns, from a corpus of 87,002; 7 matched in the 4 to 12 September 2026 window. These are reports, not evidence. [C106 data sheet, community line]
What is tesamorelin, structurally and at the receptor?
Tesamorelin is GRF(1-44) with a hexenoyl group attached to Tyr1, and its label describes binding and stimulation of the human GRF, or GHRH, receptor. The label's in-vitro comparison is with endogenous GRF and reports similar receptor potency. [EGRIFTA SV PI 11, 12.1]
The chemical modification matters separately from receptor identity. Ferdinandi reported resistance to DPP-4 deactivation in rat, dog and human plasma. Earlier human-plasma work described cleavage of GRH at the 2-3 bond and prevention of hydrolysis through D-amino acid substitution at position 1 or 2. These are molecular stability findings. [PMID 17214611; PMID 2565342]
In Stanley's study, 13 men received tesamorelin 2 mg subcutaneously once daily for 2 weeks, with their own baseline as comparator. Overnight GH changed by +0.5 ± 0.1 microg/L and IGF-I by +181 ± 22 microg/L. These measurements concern the tesamorelin study arm. [PMID 20943777]
These are the study arms of the cited trials, not an application protocol for research vials.
PeptidesDirect does not sell Egrifta. Egrifta is an approved medicine, labelled as a single agent for the approved indication in HIV-associated lipodystrophy; its prescribing information requires IGF-1 monitoring. [EGRIFTA SV PI 1, 5.2]
What is CJC-1295, and what does the DAC change?
CJC-1295 was described as a tetrasubstituted hGRF(1-29) molecule with an added albumin-binding lysine derivative; the DAC supplies that albumin-binding feature. The no-DAC form is that same backbone without the linker. [PMID 15817669; C106 data sheet, chemistry]
The randomized human CJC-1295 publications studied the DAC form. Teichman reported a half-life of 5.8 to 8.1 days. Ionescu reported preserved GH pulsatility alongside higher trough GH, illustrating that GH pulse structure and basal GH are distinct measurements. [PMID 16352683; PMID 17018654]
- Published half-life or half-time
- 8 minutes
- Comparator
- Label PK observation
- Source
- EGRIFTA SV PI 12.3
- Published half-life or half-time
- 5.8 to 8.1 days
- Comparator
- DAC study form
- Source
- PMID 16352683
- Published half-life or half-time
- 6.7 ± 0.5 minutes
- Comparator
- GHRH-(1-29)-NH2: 4.3 ± 1.4 minutes
- Source
- PMID 7962295
The table juxtaposes sources, rather than a direct comparison trial. Soule's D-Ala2 analogue is a related molecule, not a measured half-life for the complete no-DAC CJC-1295 backbone. Sermorelin is the GHRH(1-29)NH2 fragment. [PMID 7962295; PMID 8329825]
No primary human pharmacokinetic study of CJC-1295 without DAC was identified in PubMed on 2026-09-13: "CJC-1295" returned 33 records; "CJC-1295" AND ("clinical trial"[pt] OR "randomized controlled trial"[pt]) returned 2, both DAC; "CJC-1295" AND ("without DAC" OR "no-DAC" OR "modified GRF" OR "mod GRF" OR CJC-1293) returned 3, all reviews or methods. The day-scale values therefore belong specifically to the DAC publications.
Why is ipamorelin a different receptor story?
Ipamorelin acts at a GHRP-type receptor, described subsequently as the ghrelin receptor, GHS-R1a, rather than the GHRH receptor. Raun studied a pentapeptide in rat pituitary cells; Venkova's later receptor description came from a rodent model. [PMID 9849822; PMID 19289567]
Raun reported an EC50 of 1.3 ± 0.4 nmol/L for ipamorelin versus 2.2 ± 0.3 nmol/L for GHRP-6. This was a cellular GH-release assay. Its receptor assignment explains why ipamorelin belongs in a different mechanistic category from the GHRH analogues. [PMID 9849822]
What did the GHRH plus GHRP studies measure?
The cited studies measured GH responses to GHRH and GHRP stimuli, with specific molecules and experimental conditions. Bowers studied 18 men with GHRP alone, GHRH alone and both, reporting a synergistic GH-release response in the combined study conditions. That is the paper's measured endocrine result. [PMID 2108187]
Veldhuis and Bowers studied simultaneous GHRH and GHRP-2 infusion under a sex steroid clamp in 47 men and reported a negative age correlation. Tannenbaum and Bowers investigated rats and attributed the response to GHRH-dependent pathways rather than altered somatostatin release. These human and animal experiments address pathway interaction; their identities and models remain part of the result. [PMID 19240251; PMID 11322498]
Was the combination studied?
The documented searches identified no human combination trial: PubMed tesamorelin AND (GHRP OR "growth hormone-releasing peptide" OR ipamorelin) AND ("clinical trial"[pt] OR "randomized controlled trial"[pt]), searched 2026-09-13, returned 0 records. The unfiltered PubMed search (tesamorelin OR egrifta) AND (ipamorelin OR "CJC-1295" OR sermorelin OR GHRP) on 2026-09-13 returned 15 records, all reviews or methods, none interventional.
ClinicalTrials.gov API v2 searches tesamorelin AND ipamorelin and tesamorelin AND CJC-1295, dated 2026-09-13, each returned 0 registered trials. Separately, its CJC-1295 search on 2026-09-13 returned 1 record, NCT00267527: the phase 2 trial was terminated, with no results or termination reason given.
The evidence map separates shared GHRH receptor pharmacology, DAC-dependent half-life figures and experiments involving a different receptor pathway. Those categories support a mechanistic explanation, not a combination recommendation.
Products mentioned
The following catalog entries are supplied strictly for in-vitro research. Nothing on this page is a protocol, a recommendation or medical advice.
Tesamorelin is a stabilised GHRH(1-44) analogue with a trans-3-hexenoyl N-terminal modification, an agonist at the pituitary GHRH receptor. Lyophilized powder, specified purity at or above 98% (HPLC), batch CoA.
CJC-1295 without DAC (Mod GRF 1-29) is a synthetic 29-amino-acid GHRH(1-29) analog and GHRH receptor agonist. Research-grade lyophilized powder, specified purity at or above 99% (HPLC), batch-specific CoA. Laboratory use only.
Ipamorelin is a synthetic pentapeptide and a selective agonist at the GHS-R1a (ghrelin) receptor on pituitary somatotrophs. Research-grade lyophilized powder, specified purity at or above 98% (HPLC), batch CoA.
Research blend of CJC-1295 no-DAC (Modified GRF 1-29), a GHRH receptor agonist, and ipamorelin, a GHS-R1a agonist. 10 mg co-lyophilized vial or 20 mg as two sealed vials. Purity at or above 98% per component, batch CoA.
Sermorelin is the synthetic GHRH(1-29) fragment and an agonist at the pituitary GHRH receptor, formerly approved as Geref. Research-grade lyophilized powder, specified purity at or above 98% (HPLC), batch CoA.
Sources
- DailyMed. EGRIFTA SV PI, sections 1, 5.2, 11, 12.1, 12.3. SPL setid 3d783378-b02d-4f19-99dd-0fc91a042224.
- Ferdinandi 2007, PMID 17214611.
- Frohman 1989, PMID 2565342.
- Stanley 2011, PMID 20943777.
- Jette 2005, PMID 15817669.
- Soule 1994, PMID 7962295.
- Teichman 2006, PMID 16352683.
- Ionescu 2006, PMID 17018654.
- Wilton 1993, PMID 8329825.
- Raun 1998, PMID 9849822.
- Venkova 2009, PMID 19289567.
- Bowers 1990, PMID 2108187.
- Veldhuis and Bowers 2009, PMID 19240251.
- Tannenbaum and Bowers 2001, PMID 11322498.
- ClinicalTrials.gov, 2026-09-13. Phase 2 Study to Evaluate the Efficacy and Safety of CJC 1295 Administered for 12 Weeks. NCT00267527.
- Data sheet C106: tesamorelin, CJC-1295 and what a GHRP does differently. Built 2026-09-13. Absence statements, chemistry and community line.
Research use only. All catalog compounds mentioned here are supplied strictly for in-vitro research. Nothing in this article is a protocol, a recommendation or medical advice.
Research context for English-speaking buyers
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