Tesamorelin draws heavy research interest in growth-hormone-releasing-hormone (GHRH) pathway studies. It is also one of the longer peptides in a typical research catalog — and length changes everything about how you should evaluate quality.
What tesamorelin is
Tesamorelin is a synthetic analog of human GHRH(1-44) carrying a trans-3-hexenoyl modification on its N-terminus. That modification exists for a practical laboratory reason: it protects the molecule against rapid enzymatic cleavage that limits native GHRH’s usable life in biological matrices, making tesamorelin a more stable research tool for GHRH-receptor pathway work. Full length is 44 residues, with a theoretical mass around 5,136 Da.
How it differs from other GHRH-pathway research peptides
Research catalogs typically carry several compounds in this space: tesamorelin (full-length stabilized analog), sermorelin (the 1-29 fragment), CJC-1295 (a modified 1-29 with extended stability — with-DAC form available for research), and secretagogues like ipamorelin which act on the ghrelin receptor instead. They are not interchangeable in research design — receptor target and half-life profile differ across the set.
Stability and handling
- Lyophilized: −20°C for long-term storage, protected from light and moisture.
- Reconstituted: as a 44-residue peptide, solutions are less forgiving than short fragments — refrigerate, minimize freeze-thaw, use within the protocol’s validated window.
Why lot quality matters more at 44 residues
Every additional residue is another opportunity for deletion sequences and truncation impurities. On long peptides, an honest certificate matters disproportionately: ≥99% HPLC purity with the chromatogram or wavelength stated, mass-spec identity near the ~5,136 Da theoretical, and a lot number that retrieves a real document. Our guides to reading a COA and HPLC vs MS cover the details; every Heartland lot publishes in the COA portal.
Research availability
Tesamorelin research material (10mg) — ≥99% HPLC-verified with mass-spec identity per lot, shipped same-day from Tulsa, Oklahoma.
Tesamorelin is supplied strictly for in vitro laboratory research — not for human or veterinary use.