Name: Tesamorelin GHRH Analog Research Peptide
Brand: Koi Aminos
SKU: TESAMORELIN
Availability: InStock

Question 1

What is Tesamorelin?

Accepted Answer

Tesamorelin (TH9507, CAS 218949-48-5) is a synthetic stabilized analog of growth-hormone-releasing hormone (GHRH 1-44). An N-terminal trans-3-hexenoyl modification confers resistance to dipeptidyl-peptidase cleavage, providing markedly greater enzymatic stability than native GHRH(1-44) or sermorelin. It binds GHRH-R on pituitary somatotrophs and stimulates pulsatile GH release through the Gs/cAMP pathway. MW 5135.90 g/mol, formula C221H366N72O67S. It is the reference long-acting GHRH analog in endocrinology research and the active ingredient in FDA-approved Egrifta.

Question 2

What does the N-terminal trans-3-hexenoyl modification do?

Accepted Answer

The trans-3-hexenoyl group is a six-carbon alpha,beta-unsaturated fatty acid attached to the N-terminus of GHRH(1-44). Its primary function is steric: it blocks dipeptidyl-peptidase (DPP-IV and related enzymes) from cleaving the N-terminal dipeptide - the site of enzymatic degradation in native GHRH(1-44) and sermorelin. This single modification extends enzymatic stability significantly, making tesamorelin the DPP-resistant GHRH analog of choice for extended assay protocols, pharmacokinetic modeling, and any research context where peptide stability over time matters.

Question 3

How does Tesamorelin differ from Sermorelin?

Accepted Answer

Both bind GHRH-R and stimulate pulsatile GH release through Gs/cAMP, but they differ critically in length, modification, and enzymatic stability. Sermorelin is GHRH(1-29) - the minimal 29-amino-acid fragment - without N-terminal protection, subject to DPP cleavage (MW 3357.93 g/mol). Tesamorelin is GHRH(1-44) - the full sequence - with the trans-3-hexenoyl N-terminal modification blocking DPP (MW 5135.90 g/mol). Order both to run the definitive GHRH class DPP stability comparison: same receptor target, one protected, one not.

Question 4

Why does Tesamorelin preserve pulsatile GH release?

Accepted Answer

Tesamorelin acts upstream of the pituitary, stimulating GHRH-R to trigger endogenous GH synthesis and pulsatile secretion. The pituitary's own feedback mechanisms - including somatostatin inhibition - remain intact. This preserves the physiological pulsatile GH release pattern. Direct GH administration bypasses this regulatory loop entirely, suppressing endogenous GHRH signaling and eliminating pulsatility. For research examining the GH axis under physiological conditions, Tesamorelin's upstream mechanism is the more accurate model.

Question 5

What is the molecular weight of Tesamorelin?

Accepted Answer

MW 5135.90 g/mol. Molecular formula: C221H366N72O67S. CAS: 218949-48-5. The N-terminal trans-3-hexenoyl modification accounts for the higher MW vs. sermorelin (3357.93 g/mol). Tesamorelin is the heaviest GHRH analog in our catalog.

Question 6

Is Tesamorelin FDA approved?

Accepted Answer

Tesamorelin is the active ingredient in Egrifta (FDA-approved for HIV-associated lipodystrophy). Research-grade Tesamorelin sold here is a separate compound for in vitro laboratory use only. It is not approved for administration, therapeutic use, or any purpose outside laboratory research.

Question 7

What is Tesamorelin used for in research?

Accepted Answer

Tesamorelin is used for: GHRH-R binding and cAMP-accumulation assays as the long-acting reference GHRH agonist; somatotroph GH-release and IGF-1 downstream studies in cell culture and rodent models; DPP stability benchmark - comparing half-life against sermorelin (unprotected) and native GHRH(1-44); GH-axis pulsatility modeling under defined experimental conditions; structure-activity studies of N-terminally protected GHRH analogs; and secretagogue synergy experiments with GHS-R1a agonists (e.g. Ipamorelin).

Question 8

What does DPP-resistant mean in GHRH research?

Accepted Answer

DPP-resistant means the peptide resists cleavage by dipeptidyl-peptidase (DPP-IV and related enzymes) at the N-terminus. DPP enzymes cleave the first two amino acids from the N-terminus of many peptides - including native GHRH - rapidly reducing their half-life in both plasma and assay conditions. Tesamorelin's N-terminal trans-3-hexenoyl group sterically blocks this cleavage site, extending enzymatic stability far beyond unmodified GHRH sequences. This is why researchers choose tesamorelin over sermorelin or native GHRH for extended assay protocols.

Question 9

How should Tesamorelin be stored?

Accepted Answer

Store the sealed lyophilized vial at −20°C, protected from light and humidity. For long-term storage, −80°C is recommended. Short-term refrigeration at 2–8°C is acceptable for use within a few weeks. After reconstitution in sterile or bacteriostatic water at neutral pH, aliquot into single-use volumes and store at −80°C. Avoid repeated freeze-thaw cycles.

Question 10

What documentation is available with Tesamorelin?

Accepted Answer

A batch-specific Certificate of Analysis is publicly viewable. Use the lot number on your vial to access documentation covering HPLC purity (≥99%), LC-MS identity confirmation, net content, heavy metals by ICP-MS, sterility, and endotoxin.

Tesamorelin GHRH Analog Research Peptide

Key Takeaways

Key Scientific Specifications

Research-Referenced Attributes

Related Compounds

GLP-3 RT

GLP-3 R