BULKGLP RESEARCH LIBRARY
Tesamorelin, Sermorelin and Ipamorelin
Published
Tesamorelin and sermorelin are GHRH receptor agonists with different peptide structures; ipamorelin is a pentapeptide agonist of the ghrelin receptor, GHSR-1a.
At a glance
- Tesamorelin contains a modified GHRH(1–44) backbone.
- Sermorelin is GHRH(1–29)-amide, a 29-residue sequence.
- Ipamorelin has five residues and targets a different receptor.
Structure and receptor comparison
| Compound | Structural reference | Receptor |
|---|---|---|
| Tesamorelin | 44 residues; N-terminal trans-3-hexenoyl group; C-terminal amide | GHRHR |
| Sermorelin | GHRH residues 1–29; C-terminal amide | GHRHR |
| Ipamorelin | Aib-His-D-2-Nal-D-Phe-Lys-NH2 | GHSR-1a |
The FDA tesamorelin chemistry review documents the modified 44-residue structure. The sermorelin structure record identifies the shorter amidated sequence. Raun and colleagues’ original ipamorelin characterization describes its pentapeptide sequence; the NCI receptor reference identifies the ghrelin receptor target.
What the structural terms mean
- GHRH
- Growth hormone-releasing hormone, the sequence reference for tesamorelin and sermorelin.
- N-terminal modification
- The trans-3-hexenoyl group is attached at the beginning of tesamorelin’s chain.
- Amide terminus
- The peptide’s terminal group is part of its chemical identity.
- Nonstandard residues
- Ipamorelin contains Aib and D-configured residues; residue identity and stereochemistry must be specified.
Use receptor-specific controls
For in-vitro comparisons, identify the receptor expressed by the cell system before choosing a reference compound. Sharing a receptor does not establish equal potency, and activity at GHSR-1a cannot be treated as a GHRHR measurement. Record the endpoint, exposure period and reference control with each result.
Review the Tesamorelin and Sermorelin documentation for the selected material. Match each lot’s identity result to the complete modified structure, separating peptide mass from counterions and gross powder weight. The COA interpretation guide explains the required distinction between chromatographic purity and identity.