Sermorelin vs CJC-1295 vs Tesamorelin: GHRH Analog Research Overview

For Research Use Only. Not for human or veterinary use. All information below is intended for qualified research professionals at accredited institutions.

TL;DR

Sermorelin, CJC-1295 (No DAC), and Tesamorelin are all synthetic analogs of growth hormone-releasing hormone (GHRH), acting as GHRH receptor agonists at the pituitary somatotroph, but differ substantially in sequence length, structural modifications, and plasma half-life.
Sermorelin is the shortest biologically active GHRH fragment (29 AA, C-terminal amidated); CJC-1295 No DAC is a modified GHRH analog with improved DPP-IV resistance; Tesamorelin is a full-length GHRH(1-44) analog with N-terminal trans-3-hexenoic acid conjugation for further DPP-IV protection.
Selection depends on whether the research design requires short-acting pulsatile GHRH stimulation (Sermorelin), an intermediate-stability modified analog (CJC-1295 No DAC), or extended receptor engagement with a full-length GHRH sequence (Tesamorelin).

The hypothalamic-pituitary-somatotropic (HPS) axis — encompassing hypothalamic GHRH secretion, pituitary GH release, and downstream IGF-1 production — is a central regulator of somatic growth, body composition, and metabolic homeostasis. Research into GHRH receptor pharmacology has produced a series of synthetic GHRH analogs with distinct structural features and pharmacokinetic profiles. Sermorelin, CJC-1295 (No DAC), and Tesamorelin are three such analogs, each representing a different approach to GHRH receptor engagement. This overview compares their structures, mechanisms, and research applications for investigators studying the GH secretory axis.

Background: GHRH Biology and the DPP-IV Problem

Endogenous GHRH is a 44-amino-acid peptide secreted from hypothalamic neurons that binds the GHRH receptor (GHRHR) on pituitary somatotroph cells, stimulating cAMP production and GH secretion. Native GHRH has a very short plasma half-life (approximately 2–5 minutes) due to rapid N-terminal cleavage by dipeptidyl peptidase-IV (DPP-IV), which cleaves after the second amino acid (Ala² in GHRH), inactivating the peptide. The first two residues (Tyr¹-Ala²) are essential for receptor binding activity — DPP-IV cleavage removes them and abolishes activity.

Synthetic GHRH analogs for research have addressed this vulnerability through various structural strategies: truncation to the minimal active fragment (Sermorelin), amino acid substitutions at position 2 to block DPP-IV cleavage (CJC-1295 No DAC), and N-terminal modifications combined with full-length sequence retention (Tesamorelin).

Sermorelin: GHRH(1-29)NH₂

Sermorelin is a synthetic peptide corresponding to the first 29 amino acids of human GHRH with C-terminal amidation (GHRH(1-29)NH₂). It was the first synthetic GHRH fragment demonstrated to retain full GHRHR binding activity, establishing that the C-terminal residues 30–44 of GHRH are not required for receptor activation.

Minimal active fragment: Systematic truncation studies of GHRH established the minimal sequence for full receptor binding and activation. The first 29 residues — with C-terminal amidation to prevent exopeptidase degradation from the C-terminus — retain complete binding affinity and agonist efficacy at GHRHR. This makes Sermorelin the reference “minimal GHRH agonist” for structure-activity relationship (SAR) studies comparing shorter fragments or modified sequences.

Pharmacokinetics: Despite the C-terminal amidation, Sermorelin retains susceptibility to N-terminal DPP-IV cleavage (at the Tyr¹-Ala² bond), resulting in a plasma half-life of approximately 10–20 minutes in research model systems — longer than native GHRH but shorter than DAC-modified or N-terminally protected analogs. This pharmacokinetic profile makes Sermorelin suitable for research designs requiring acute, pulsatile GHRH receptor stimulation.

Research applications: Sermorelin is used as a reference GHRH agonist in somatotroph cell pharmacology studies, receptor binding competition assays, pituitary axis biology research, and as a positive control for GH secretion assays. Its extensive prior characterization in the literature makes it a well-validated research tool with a large body of comparative data.

Key specifications:

CAS: 86168-78-7
MW: 3,357.96 Da
Sequence: GHRH(1-29)NH₂ (29 AA, C-terminal amide)
Purity: ≥99% HPLC
Available: 10mg × 10 vials
Storage: -20°C, desiccated
Product page: glunovabiotech.com/products/sermorelin

CJC-1295 (No DAC): DPP-IV-Resistant GHRH Analog

CJC-1295 (No DAC) is a synthetic GHRH analog incorporating amino acid substitutions designed to resist DPP-IV cleavage while retaining GHRHR binding activity. The “No DAC” designation distinguishes it from the DAC-conjugated form, indicating the absence of a Drug Affinity Complex (reactive maleimide linker for covalent albumin binding).

DPP-IV resistance strategy: The key modification in CJC-1295 is substitution at the DPP-IV recognition site — specifically an Ala² → D-Ala² or equivalent modification (the exact substitution pattern in different CJC variants has been published in the primary literature) that sterically or conformationally blocks DPP-IV substrate recognition while maintaining receptor-binding capacity. This modification extends plasma half-life compared to native GHRH and Sermorelin without requiring albumin conjugation.

Half-life profile (No DAC): Without the DAC albumin-binding moiety, CJC-1295 No DAC has an intermediate plasma half-life (estimated 30 minutes to several hours in various research systems) — significantly longer than Sermorelin but substantially shorter than the DAC-conjugated version. This intermediate pharmacokinetic profile positions it between a short-acting reference compound and a long-acting depot formulation for experimental design purposes.

Research applications: CJC-1295 No DAC is used in research designs requiring sustained but non-depot GHRH receptor stimulation. It is useful for studying somatotroph GH secretion dynamics over intermediate time courses, comparing DPP-IV-resistant vs. native GHRH sequence activity in receptor pharmacology assays, and as an intermediate-stability reference in comparative GHRH analog studies.

Key specifications:

CAS: 863288-34-0
MW: ~3,367 Da
Purity: ≥99% HPLC
Available: 10mg × 10 vials
Storage: -20°C, desiccated
Product page: glunovabiotech.com/products/cjc-1295

Tesamorelin: Full-Length GHRH Analog with N-Terminal Protection

Tesamorelin is a synthetic analog of full-length human GHRH (44 amino acids) with a trans-3-hexenoic acid moiety conjugated at the N-terminus (Tyr¹ α-amino group). This N-terminal fatty acid modification provides steric protection against DPP-IV cleavage at the Tyr¹-Ala² bond while preserving the full GHRH receptor interaction surface.

N-terminal modification strategy: Unlike the internal amino acid substitution approach in CJC-1295, Tesamorelin uses N-terminal chemical conjugation to block DPP-IV access. The trans-3-hexenoic acid moiety modifies the α-amino group of Tyr¹, eliminating the free amino group required for DPP-IV substrate recognition. This modification has been shown in published research to extend plasma stability relative to unmodified GHRH while maintaining GHRHR binding through the intact peptide backbone.

Full-length sequence: Tesamorelin retains all 44 amino acids of human GHRH, in contrast to Sermorelin (29 AA) and CJC-1295 variants (which use modified shorter sequences). This means the full receptor contact surface of GHRH is preserved. Research into the structural determinants of GHRHR binding has used Tesamorelin as a full-length reference to study how C-terminal residues (30–44) contribute to binding affinity, receptor activation kinetics, or signal transduction dynamics compared to the truncated Sermorelin.

Key specifications:

CAS: 901758-09-6
MW: ~5,136 Da
Modification: trans-3-hexenoic acid at N-terminus
Purity: ≥99% HPLC
Available: 10mg × 10 vials
Storage: -20°C, desiccated
Product page: glunovabiotech.com/products/tesamorelin

Three-Way Comparison Table

Parameter	Sermorelin	CJC-1295 (No DAC)	Tesamorelin
CAS	86168-78-7	863288-34-0	901758-09-6
Sequence	GHRH(1-29)NH₂	Modified GHRH analog	GHRH(1-44) + N-terminal modification
Amino acid length	29 AA	~29-30 AA	44 AA
MW	3,357.96 Da	~3,367 Da	~5,136 Da
DPP-IV resistance strategy	None (susceptible)	AA substitution at DPP-IV site	N-terminal trans-3-hexenoic acid conjugation
Approximate research half-life	~10–20 min	~30 min to several hours	Hours (extended vs. GHRH)
Albumin binding (DAC)	No	No (No DAC form)	No (fatty acid is DPP-IV shield, not albumin binder)
Full GHRH sequence	No (1-29 fragment)	No (modified truncation)	Yes (1-44, N-term modified)
Available packaging	10mg × 10 vials	10mg × 10 vials	10mg × 10 vials
Purity	≥99% HPLC	≥99% HPLC	≥99% HPLC

Research Applications by Compound

Sermorelin:

GHRHR binding competition and saturation binding assays (reference agonist)
Acute GH secretion studies in somatotroph cell lines or primary pituitary cultures
cAMP and PKA pathway activation assays following GHRH receptor stimulation
Comparative SAR studies of GHRH truncation variants
Pulsatile HPS axis modeling in rodent studies

CJC-1295 (No DAC):

Intermediate-duration GHRH receptor stimulation studies where DPP-IV sensitivity must be controlled
Comparative pharmacology against Sermorelin to characterize the effect of DPP-IV resistance on receptor engagement duration
GH secretion dynamics over 1–6 hour windows in cell or animal model systems
Studies requiring enhanced peptide stability in plasma or serum-containing media

Tesamorelin:

Full-length GHRH sequence binding studies characterizing the contribution of residues 30–44 to GHRHR pharmacology
Comparative receptor activation studies (Tesamorelin vs. Sermorelin for mechanistic dissection of C-terminal GHRH contributions)
Sustained GHRH axis stimulation experiments requiring a full-sequence, DPP-IV-stabilized agonist
Visceral adipose tissue biology research in metabolic model systems

Ordering Information

All three GHRH analogs are available from Glunova Biotech LLC at ≥99% HPLC purity with full COA per lot. Ipamorelin (GHS-R1a agonist) and GHRP-6 are also available for GH axis research requiring ghrelin-pathway engagement alongside GHRH receptor activation:

For bulk research orders, institutional pricing, COA, SDS, or supply agreements: dylan.tom2012@gmail.com | +1 (586) 248-1681. Responses within 1 business day.

For Research Use Only. Not for human or veterinary use. These products have not been evaluated by the FDA or any regulatory agency for safety or efficacy in humans or animals.