Description

Product Specifications

Field	Details
Product Name	Tesamoreln
CAS Number	218949-48-5
Molecular Formula	C₂₂₁H₃₆₆N₇₂O₆₇S
Molecular Weight	≈ 5135.9 Da
Amino Acid Sequence	trans-3-hexenoyl–Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg-Gln-Gln-Gly-Glu-Ser-Asn-Gln-Glu-Arg-Gly-Ala-Arg-Ala-Arg-Leu-NH₂
Length	44 amino acids (full-length GHRH analog with N-terminal modification)
N-Terminal Modification	trans-3-hexenoic acid group (confers enzymatic resistance)
Form	Lyophilized powder (not reconstituted)
Purity	≥98% (HPLC verified)
Third-Party Testing	Janoshik Analytical — Certificate of Analysis available
Storage	−20°C (unreconstituted). Protect from light and moisture.
Vial	3 mL sealed vial with flip-top cap
Content	10 mg per vial

Molecular Profile

Tesamoreln is a synthetic analog encompassing all 44 amino acids of the endogenous human GHRH sequence, with a single structural modification: the addition of a trans-3-hexenoic acid moiety to the N-terminal tyrosine residue. This lipophilic modification was engineered to confer resistance to dipeptidyl peptidase IV (DPP-IV) and other aminopeptidases that rapidly degrade native GHRH in biological matrices. The resulting compound has a molecular weight of approximately 5135.9 Da and the molecular formula C₂₂₁H₃₆₆N₇₂O₆₇S.

Receptor Interaction and Signaling Pathways

In preclinical models and in vitro systems, Tesamoreln was observed to bind to the growth hormone–releasing hormone receptor (GHRHR), a Class B G-protein coupled receptor expressed on anterior pituitary somatotroph cells. Receptor engagement was reported to activate the stimulatory G-protein (Gₐ)/adenylate cyclase pathway, increasing intracellular cyclic adenosine monophosphate (cAMP) concentrations. Downstream cAMP-dependent protein kinase A (PKA) activation was studied for its role in phosphorylation of transcription factors including CREB. Research also examined calcium-mediated second messenger pathways, nitric oxide synthase modulation, and mitogen-activated protein kinase (MAPK) signaling as parallel mechanisms following GHRHR activation.

Structural and Analytical Characterization

Tesamoreln identity and purity are characterized through reversed-phase high-performance liquid chromatography (RP-HPLC) and electrospray ionization mass spectrometry (ESI-MS). The trans-3-hexenoic acid modification at the N-terminus differentiates this compound from unmodified GHRH (1–44) and from shorter GHRH fragments such as GRF 1–29. Like other GHRH-family peptides, the methionine residue at position 27 represents a site of potential oxidative degradation, requiring storage under inert atmosphere at −20°C in lyophilized form. Reconstituted solutions should be refrigerated at 2–8°C and used promptly.

Laboratory Research Applications

Tesamoreln has been utilized in laboratory research to investigate GHRHR pharmacology, cAMP/PKA signaling fidelity, and hypothalamic–pituitary axis dynamics. Researchers examined the compound’s extended half-life (estimated at 26–38 minutes in pharmacokinetic studies, compared to 5–7 minutes for native GHRH) as a variable in studying sustained receptor activation patterns and pulsatile signaling dynamics. In cell culture models, studies examined receptor binding kinetics, downstream phosphorylation cascades, and GH gene transcription. In animal research models, investigators explored GH/IGF-1 axis interactions, adipose tissue signaling pathways, and hepatic lipid metabolism markers.

Quality and Supply

Each lot of Tesamoreln from Peptide Minds undergoes third-party analytical testing by Janoshik Analytical to verify identity, purity (≥98% by HPLC), and absence of microbial contamination. Certificates of Analysis are available upon request.

⚠️ RESEARCH USE ONLY This product is sold exclusively for laboratory research, in-vitro testing, and analytical applications. NOT for human consumption, veterinary use, clinical application, or any in-vivo use. Peptide Minds is a chemical research compound supplier. We are NOT a pharmacy, compounding facility, or medical provider.

⚠️ REGULATORY STATUS A compound with the same peptide sequence was FDA-approved (2010) under the brand name Egrifta® for a specific indication. Updated formulations (Egrifta SV, Egrifta WR) were introduced between 2019 and 2023. This product is a research compound. It is not the marketed pharmaceutical product and is not FDA-approved for any therapeutic, diagnostic, or clinical use. The name Tesamoreln is a proprietary product identifier used by Peptide Minds.

✅ QUALITY ASSURANCE Third-party tested by Janoshik Analytical. Certificate of Analysis (COA) available for each lot. ≥98% purity verified by HPLC. Manufactured under controlled conditions with full traceability.

Research Background

Discovery and Development History

The development of enzymatically stable GHRH analogs represented a long-standing objective in peptide chemistry. Endogenous human GHRH, a 44-amino acid neuropeptide secreted by the arcuate nucleus of the hypothalamus, exhibited a circulating half-life of approximately 5 to 7 minutes due to rapid cleavage by dipeptidyl peptidase IV (DPP-IV) at the Tyr¹–Ala² bond. This rapid degradation limited the utility of unmodified GHRH as a research tool for studying sustained receptor activation dynamics.

Theratechnologies, Inc. of Montreal, Canada, developed a modified GHRH analog designated TH9507, which incorporated a trans-3-hexenoic acid group at the N-terminal tyrosine residue. This lipophilic modification was designed to sterically shield the DPP-IV cleavage site while simultaneously increasing receptor binding affinity at the GHRHR. Preclinical pharmacokinetic studies demonstrated that the modified compound exhibited substantially extended plasma stability compared to native GHRH, permitting sustained receptor engagement in experimental systems.

The compound advanced through Phase 2 and Phase 3 clinical studies examining its effects on visceral adipose tissue parameters in a specific patient population. In November 2010, the FDA approved the compound under the brand name Egrifta® for a defined indication. Updated single-vial (Egrifta SV) and wide-range (Egrifta WR) formulations were introduced between 2019 and 2023. It remains the only GHRH analog to have received FDA approval for any indication.

Structural Characteristics and N-Terminal Modification

Tesamoreln retains the complete 44-amino acid sequence of endogenous human GHRH with a single chemical modification: conjugation of trans-3-hexenoic acid to the α-amino group of the N-terminal tyrosine. This unsaturated fatty acid moiety introduces a lipophilic extension that serves dual structural functions. First, it creates steric hindrance at the DPP-IV cleavage site between positions 1 and 2, reducing susceptibility to the primary enzymatic degradation pathway that limits native GHRH bioavailability. Second, the modification was reported to increase binding affinity at the GHRHR compared to the unmodified peptide, based on competitive binding assay data from preclinical studies.

In contrast to truncated GHRH fragments such as GRF 1–29 (sermorelin), Tesamoreln retains the C-terminal 15 residues (positions 30–44). While these residues were not considered essential for receptor binding in the GRF 1–29 structure–activity studies, the full-length sequence may contribute to secondary structural stability and receptor interaction kinetics. The C-terminal amidation (Leu⁴⁴-NH₂) is consistent with the endogenous GHRH post-translational modification and contributes to resistance against carboxypeptidase-mediated degradation.

As with other GHRH-family peptides, the methionine residue at position 27 represents a site of oxidative vulnerability. Methionine sulfoxide formation was identified as the primary degradation pathway under suboptimal storage conditions, monitored by shifts in HPLC retention time and corresponding mass spectral changes. Standard handling protocols require lyophilized storage at −20°C under inert atmosphere with protection from light.

GHRH Receptor Systems Studied in Research

The growth hormone–releasing hormone receptor (GHRHR) is a Class B (secretin-like) G-protein coupled receptor predominantly expressed on anterior pituitary somatotroph cells. Tesamoreln was utilized as a reference agonist in studies mapping GHRHR binding kinetics, receptor activation thresholds, and desensitization patterns. Its extended half-life compared to native GHRH made it particularly useful for studying sustained versus pulsatile receptor engagement dynamics.

Upon GHRHR engagement, the receptor was reported to couple primarily to the stimulatory G-protein (Gₐ), activating adenylate cyclase and increasing intracellular cAMP. Downstream, cAMP-dependent PKA phosphorylated transcription factors including CREB, which was studied as a regulatory step in GH gene expression. Calcium influx through voltage-gated channels was examined as a co-regulatory mechanism contributing to GH vesicular exocytosis. Additional studies investigated nitric oxide synthase (NOS) modulation and mitogen-activated protein kinase (MAPK) pathway involvement as parallel signaling cascades downstream of GHRHR activation.

The interplay between GHRHR and somatostatin receptor (SSTR) signaling was a recurring research focus. Somatostatin, acting through SSTR2 and SSTR5 subtypes, was reported to inhibit cAMP production and counteract GHRHR-mediated signaling. Tesamoreln’s ability to stimulate GH release while somatostatin-mediated inhibitory control remained intact was studied as a mechanism preserving physiological pulsatile secretion patterns, in contrast to the tonic elevation produced by exogenous GH administration.

Researchers also examined the interaction between GHRHR signaling (activated by Tesamoreln) and GHS-R1a (ghrelin receptor) signaling. Preclinical models explored whether co-activation of these distinct receptor pathways produced signaling amplitudes exceeding the additive effects of either pathway alone. Pituitary cell culture studies reported substantially greater GH secretory responses when GHRH-pathway and ghrelin-pathway stimulation were combined, a finding attributed to convergent but mechanistically distinct intracellular signaling cascades.

Adipose Tissue and Hepatic Lipid Metabolism Research

A significant body of preclinical and translational research examined Tesamoreln in the context of adipose tissue biology and lipid metabolism pathways. In research models, GH axis activation was studied for its effects on hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) activity, as well as suppression of lipoprotein lipase (LPL), shifting adipocyte metabolic profiles toward triglyceride mobilization. Studies noted that visceral adipose tissue (VAT) deposits exhibited differential sensitivity to GH-mediated signaling compared to subcutaneous adipose tissue, attributed to depot-specific receptor density, vascular architecture, and adipokine signaling profiles.

Hepatic lipid metabolism research examined how GH/IGF-1 signaling pathways influenced fatty acid oxidation rates, de novo lipogenesis, and portal free fatty acid flux. Preclinical studies investigated markers of hepatic triglyceride content and steatosis-related endpoints as downstream correlates of GH axis modulation. These studies contributed to ongoing research interest in GHRH receptor pharmacology as a tool for investigating lipid metabolism pathways in controlled experimental settings.

Laboratory Methodologies

In vitro studies utilized primary pituitary cell cultures and immortalized somatotroph cell lines to examine Tesamoreln’s effects on intracellular cAMP concentrations, calcium mobilization, GH mRNA transcription, and GH protein secretion. Radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) techniques quantified GH and IGF-1 levels in conditioned media at varying concentrations and time points. Receptor binding assays employed radiolabeled GHRH analogs to characterize competitive displacement kinetics and binding affinity constants.

In animal research models, investigators administered the compound via subcutaneous injection to study GH secretory dynamics over defined observation windows. Serial blood sampling at timed intervals permitted construction of GH pulsatility profiles and area-under-curve (AUC) calculations. Comparative pharmacokinetic studies evaluated half-life differences between Tesamoreln and unmodified GHRH or shorter GHRH fragments, establishing the impact of the trans-3-hexenoic acid modification on plasma stability and receptor occupancy duration.

Body composition studies in animal models employed computed tomography (CT) imaging for quantification of visceral and subcutaneous adipose tissue compartments, magnetic resonance spectroscopy (MRS) for hepatic lipid content assessment, and dual-energy X-ray absorptiometry (DEXA) for lean mass measurements.

Analytical Characterization

Standard analytical methods for Tesamoreln characterization include reversed-phase HPLC for purity assessment, electrospray ionization mass spectrometry (ESI-MS) for molecular weight confirmation at the expected m/z ratio consistent with 5135.9 Da, and amino acid composition analysis following acid hydrolysis for sequence verification. The trans-3-hexenoic acid modification is confirmed by characteristic retention time shifts and mass spectral fragmentation patterns distinguishing the modified compound from unmodified GHRH (1–44).

Stability studies established that lyophilized material maintained integrity for extended periods at −20°C, while reconstituted solutions exhibited measurable degradation within days at ambient temperature. Methionine oxidation at position 27 was identified as the primary degradation pathway, consistent with other GHRH-family peptides.

References

1. Halmos, G., Szabo, Z., Dobos, N., Juhasz, E., & Schally, A. V. (2025). Growth hormone-releasing hormone receptor (GHRH-R) and its signaling. Reviews in Endocrine & Metabolic Disorders, 26(3), 343–352.
2. Olarescu, N. C., Gunawardane, K., Hanson, T. K., et al. (2025). Normal Physiology of Growth Hormone in Normal Adults. Endotext. South Dartmouth (MA): MDText.com, Inc.
3. Kopchick, J. J., Berryman, D. E., Puri, V., Lee, K. Y., & Jørgensen, J. O. (2019). The effects of growth hormone on adipose tissue: Old observations, new mechanisms. Nature Reviews Endocrinology, 16(3), 135.
4. Lake, J. E., La, K., Erlandson, K. M., et al. (2021). Tesamoreln improves fat quality independent of changes in fat quantity. AIDS, 35(9), 1395–1402.
5. Gertner, J. M., et al. (2002). Pharmacokinetic and pharmacodynamic studies of Tesamoreln (TH9507). Referenced in Phase 2/3 clinical development program, Theratechnologies, Inc.

Compliance Statement

LEGAL DISCLAIMER — RESEARCH USE ONLY FOR RESEARCH USE ONLY. NOT FOR HUMAN CONSUMPTION OR VETERINARY USE. This product is sold exclusively for laboratory research applications, in-vitro testing, and analytical purposes. It is not approved by the FDA for human use, clinical applications, therapeutic purposes, or diagnostic use outside of its originally approved pharmaceutical context. Not intended to diagnose, treat, cure, or prevent any disease or medical condition. Peptide Minds (operated by Accelairate LLC) is a research chemical compound supplier. We are not a pharmacy, compounding facility, or medical provider. Products are manufactured and sold under Research Use Only (RUO) classification. This product is not the marketed pharmaceutical product Egrifta®, Egrifta SV®, or Egrifta WR®. The compound name Tesamoreln is a proprietary product identifier used by Peptide Minds and should not be equated with any FDA-approved drug product. By purchasing this product, the buyer acknowledges that it will be used solely for qualified laboratory research purposes and agrees to comply with all applicable federal, state, and local regulations governing the purchase and use of research compounds. All research references cited are from peer-reviewed published literature provided for informational context only. Inclusion of research citations does not constitute claims of product efficacy for any application.