Tesamorelin vs Ipamorelin — GRF Analogue vs Pentapeptide
Tesamorelin and ipamorelin are both synthetic growth-hormone-related research peptides, but they are very different molecules: a 44-residue GRF analogue versus a 5-residue pentapeptide. This page sets out the factual differences.
Last updated: 2026-08-21 · By: Index Peptides technical team
| Tesamorelin | Ipamorelin | |
|---|---|---|
| Type | GRF(1-44) analogue | Pentapeptide secretagogue |
| Residues | 44 | 5 |
| CAS number | 218949-48-5 | 170851-70-4 |
| Molecular weight | ~5135.8 g/mol | ~711.9 g/mol |
| Research context | GRF analogue research | GH secretagogue research |
| Index Peptides formats | 10mg | 5mg |
Very different molecules
Tesamorelin is a synthetic 44-residue analogue of growth hormone releasing factor (GRF 1-44). Ipamorelin is a synthetic pentapeptide studied as a growth hormone secretagogue. The size difference alone — roughly 5135.8 g/mol versus 711.9 g/mol — reflects how different the two molecules are.
Chemistry
Tesamorelin is CAS 218949-48-5; ipamorelin is CAS 170851-70-4. Both are supplied as lyophilised powders and are commonly handled as acetate salts; the exact form is recorded on each batch's certificate of analysis.
Research literature
Tesamorelin appears in the published literature as a GRF analogue studied in clinical and preclinical research contexts. Ipamorelin appears in preclinical growth-hormone signalling literature. In both cases the research context is distinct, and Index Peptides takes no position on any application.
Regulatory status
Neither compound is an approved medicine in the UK market context, and both are prohibited in sport by the World Anti-Doping Agency (WADA). Index Peptides supplies both strictly for in-vitro laboratory research — not for human or veterinary use of any kind.
Frequently asked questions
How do tesamorelin and ipamorelin differ?
Tesamorelin is a 44-residue GRF(1-44) analogue; ipamorelin is a 5-residue pentapeptide. They are structurally unrelated compounds with different CAS numbers and molecular weights.
Are they interchangeable?
No. They are different molecules studied in different research contexts. Index Peptides supplies each strictly for in-vitro laboratory research and takes no position on any application.
How do I verify the identity of each?
Every released batch of either peptide is HPLC purity tested and LC-MS identity confirmed, with the COA on the product page and batch lookup by lot number.
References
Research use only. Not for human or animal consumption.