Guide
Tesamorelin: A Research Peptide Overview
Tesamorelin is a synthetic analogue of growth-hormone-releasing hormone, distinguished by a modification at its N-terminus. This overview covers what it is, the receptor pharmacology examined in vitro, how it is handled as a reference material, and why batch-level purity matters. It is written for laboratory research context only and makes no human-use claims.
What tesamorelin is
Tesamorelin is a 44-amino-acid synthetic analogue of growth-hormone-releasing hormone (GHRH), carrying a trans-3-hexenoic acid modification at the N-terminus. It carries CAS number 901758-09-6, the molecular formula C221H366N72O67S, and a molecular weight of 5135.90 g/mol.
That N-terminal modification is the structural feature distinguishing it from the unmodified GHRH sequence, and it is a frequent subject of peptide-stability work.
Why it is studied
In laboratory research tesamorelin is used in GHRH-receptor binding and signaling assays, where the question is how the modified N-terminus changes receptor interaction relative to the native sequence.
It also appears in endocrine-pathway research in cell-culture models, in N-terminal modification and peptide-stability studies, and as an analytical reference standard. No medical, therapeutic, or diagnostic claims are made.
Handling and storage
Tesamorelin is stored at 2°C to 8°C (36–46°F) and is not frozen, and it is protected from UV. Cold-chain handling documentation accompanies the reference material — a detail worth checking, because a peptide that has been temperature-cycled is a different sample from the one that was tested.
This overview does not cover preparation or use of any kind. That falls outside laboratory research reference use, and we do not provide that guidance.
Why purity and identity matter
A modified peptide raises a specific analytical question: is the modification actually present, and is it intact? Mass spectrometry answers it by measuring the observed molecular weight against the theoretical mass of the expected structure — a purity percentage alone cannot.
This is why a per-batch Certificate of Analysis — one tied to the exact lot you receive — is more useful than a generic brand-level document.
How to verify a tesamorelin batch
Before relying on any batch, confirm three things: purity (an HPLC percentage), identity (a mass-spectrometry confirmation), and a traceable lot number with a test date. If the supplier lets you look up that batch’s report, you can match the documentation to the vial in hand.
See our guide on how to read a peptide COA for a field-by-field walkthrough.