Molecular Structure Explorer
Tesamorelin
Structure of the compound covered in this guide.
Last reviewed: October 2026 · Cleared Peptides research team
Research use only. Tesamorelin: Research Guide to the GHRH Analog is supplied for laboratory research. It is not a drug, food, cosmetic, or dietary supplement. It is not FDA-approved. It is not for human or veterinary administration. This page does not give a dose or a method of administration. A study cited on this page describes that study’s own test article. It does not make this lot an approved medicine. To check a fact, open the PubMed or DOI link, confirm the authors and year, and match the paper’s compound name, CAS number, or sequence to the specification table. The full method is on the research desk page. Identity and purity for a lot are only what that lot’s certificate of analysis reports. An HPLC percentage is not a sterility result and not an endotoxin result unless the certificate prints those tests.
Tesamorelin (TH9507) is a synthetic analog of the full 44-amino-acid growth-hormone-releasing hormone (GHRH) bearing an N-terminal trans-3-hexenoyl group. It is a reference agonist in GHRH-receptor research.
Tesamorelin Structure and Identifiers
| Name | Tesamorelin |
|---|---|
| Code | TH9507 |
| CAS number | 218949-48-5 |
| PubChem CID | 16137828 |
| Molecular formula | C221H366N72O67S |
| Molecular weight | ≈5135.9 g/mol |
| Length | 44 residues |
| Form | Lyophilized powder |
Design
Native GHRH is rapidly inactivated by dipeptidyl peptidase-4 cleavage at its N-terminus. The hexenoyl modification protects this site, a design studied in peptide-stability research.
Tesamorelin vs Ipamorelin
| Tesamorelin | Ipamorelin | |
|---|---|---|
| Receptor | GHRH receptor | GHS-R1a (ghrelin receptor) |
| Length | 44 residues | 5 residues |
See the ipamorelin guide.
This summary describes laboratory research only and makes no claim about effects in humans or animals.
Purity Testing and Storage
Every lot of Tesamorelin supplied by Cleared Peptides is tested by an independent laboratory for identity and purity (or composition, for multi-component preparations), and the lot Certificate of Analysis is published on our COA page. Store lyophilized Tesamorelin at −20 °C, sealed, dry and protected from light. Allow the vial to reach room temperature before opening and minimize freeze–thaw cycles. Handle according to your institution’s chemical-hygiene procedures.
Research materials referenced in this guide
Analytical testing notes for Tesamorelin
Tesamorelin is identified in this guide as CAS 218949-48-5, formula C221H366N72O67S, listed mass ≈5135.9 g/mol. An identity test compares a measurement with those values. A mass spectrum is the usual measurement for a peptide. FTIR, when a certificate uses it, is a supporting infrared fingerprint and is less specific for closely related sequences.
Tesamorelin carries a fatty-acid or other lipophilic modification, so it is among the later-eluting peptides on a C18 column. Laboratories often raise the acetonitrile fraction, the column temperature, or move to a C8 or C4 column so the main peak is sharp enough to integrate. The mass used for identity has to include the lipid chain and linker, not only the amino-acid backbone. Area-percent purity still ignores water and counterion.
HPLC purity for this material is an area-percent result at the wavelength and gradient the laboratory states, commonly ultraviolet detection near 214 nm on a reversed-phase column. The instrument is a gradient pump, injector, column oven, and UV or diode-array detector. That percentage is not the number of milligrams in the vial. Water, acetate, trifluoroacetate, and other UV-silent material can dominate the gross weight while the purity figure stays high. Net peptide content, from an assay or amino-acid analysis, is the separate result to read when the certificate reports it.
A sterility test and an endotoxin test are not included in a chemical purity result. The compendial sterility test is a culture method (USP <71>): membrane filtration or direct inoculation into fluid thioglycollate medium and soybean-casein digest medium, incubated for 14 days. A PCR sterility screen uses a thermal cycler to detect microbial DNA and is a different method. The endotoxin test (USP <85> LAL, or USP <86> recombinant Factor C) reports endotoxin units with an incubating reader or a cartridge reader. Use a result only when that method is printed on the lot certificate. One published example in this catalog states that the report does not cover microbial contamination or endotoxins. The full description of equipment, standards, and how US laboratory accreditation works is in peptide analytical testing. Lot records are on the COA page.
Frequently Asked Questions
What receptor does tesamorelin act on?
The growth-hormone-releasing hormone receptor (GHRHR), a class B GPCR.
Is Tesamorelin for human use?
No. Cleared Peptides supplies Tesamorelin for laboratory research use only; it is not for human or veterinary use.
Written by the Cleared Peptides Research Desk, the editorial desk of Cleared Wellness Group LLC. This is not a personal profile of a physician or a scientist, and it is not a fictional author. The checking method is public on the research desk page. Last reviewed October 2026.
Tesamorelin research note: a GHRH analogue, and a trial that is not this vial
Research use only. This tesamorelin material is for laboratory research, code TH9507, CAS 218949-48-5. It is not the finished drug used in the NEJM trial, and this note does not repeat that trial’s dose.
The paper, bounded
Falutz, Allas, Blot, and colleagues (New England Journal of Medicine, 2007) randomized adults with HIV and an accumulation of abdominal fat to a growth hormone-releasing factor analogue, tesamorelin, or to placebo, for 26 weeks. The primary endpoint was the change in visceral adipose tissue on computed tomography. IGF-I rose in the tesamorelin arm, which is the endocrine marker expected if a GHRH analogue increased growth-hormone secretion in that study. Lipids moved in the directions the abstract reports. Those sentences describe the trial. They do not describe a lyophilized research lot, and they are not an invitation to reproduce the protocol. PubMed 18057338, DOI 10.1056/NEJMoa072375.
The catalog specification is a 44-residue GHRH analogue with an N-terminal trans-3-hexenoyl group, formula C221H366N72O67S, mass about 5135.9 g/mol. The hexenoyl modification is part of the identity. A 44-residue peptide with a free N-terminus is a different mass. The receptor in this design is the GHRH receptor on pituitary somatotrophs.
Not ipamorelin, and not a blend with MOTS-c
Ipamorelin, in Raun’s 1998 paper, releases growth hormone through a GHRP-like receptor, the pathway later named for ghrelin, and its sequence is a pentapeptide. Tesamorelin is a long GHRH analogue. Both papers are about growth hormone, and they are not the same mechanism. See ipamorelin.
This catalog does not sell MOTS-c mixed with tesamorelin. MOTS-c is a mitochondrial 16-mer. Combining the names does not combine the evidence. That distinction is its own page.
How to verify this note
- Open Falutz 2007 and confirm tesamorelin, the HIV population, the CT endpoint, and the IGF-I change. Leave the dose in the paper.
- Match CAS 218949-48-5, the 44-residue length, and the trans-3-hexenoyl N-terminus to the certificate.
- Do not accept an ipamorelin mass (about 711.9) or a MOTS-c mass (about 2174.6) as confirmation of tesamorelin.
Selected References
Peer-reviewed literature on the compounds discussed in this guide, listed as scientific background for laboratory researchers. Citation does not imply endorsement by the authors or any use other than in-vitro research.
- Memdouh S, et al. Advances in the detection of growth hormone releasing hormone synthetic analogs. Drug Test Anal. 2021;13(11-12):1871-1887. PubMed 34665524 · DOI
Laboratory note: solubility depends on salt form and solvent. This guide does not state a single solubility figure. Handling of lyophilized material is described in the peptide storage guide.
Research Use Only Notice
This guide is provided for educational and laboratory reference purposes. It summarizes published, primarily in-vitro and structural research literature and does not describe, recommend or imply any use in humans or animals. Products sold by Cleared Peptides are for laboratory research use only; they are not drugs, foods, cosmetics or dietary supplements, are not FDA-approved, and are not intended to diagnose, treat, cure, mitigate or prevent any disease. No dosing, administration or therapeutic information is provided.
