Teal HPLC chromatogram peak above an amber mass-spectrometry stick spectrum on a dark grid, representing confirming tesamorelin identity by CAS and mass spec.

"Tesa" / Tesamorelin Naming: Confirming Compound Identity by CAS and MS

Key takeaways

Tesa is informal shorthand for tesamorelin; identity is confirmed by data, not by the name.
Do not confuse it with tesofensine (a small molecule), sermorelin or ipamorelin.
The listing gives acetate-form CAS 901758-09-6 and 5195.908 g/mol; the parent peptide is near 5135.9 Da.
MS should show about 5135.9 Da deconvoluted; about 5039.7 Da indicates a missing hexenoyl cap.
For in vitro research use only.

"Tesa" is informal shorthand for tesamorelin, and a tesa peptide is confirmed as the right compound by matching its CAS number, formula and mass-spectrometry result, not by the name on a label. This guide lists what the name can be confused with and the identifiers to check. The compound background is in the tesamorelin structure and in-vitro research profile.

What does "tesa" refer to?

The word has no formal standing; it is a short form of tesamorelin, the nonproprietary name of the trans-3-hexenoyl GRF(1-44) analog sold by Happy Peptides as Tesamorelin. Because shorthand invites mix-ups, identity should be confirmed from analytical data.

Which similar names are different compounds?

Name	What it is
Tesamorelin	44-residue GHRH analog, GHRH receptor
Tesofensine	Small-molecule monoamine reuptake inhibitor, not a peptide
Sermorelin	29-residue GRF(1-29)-NH2 fragment
Ipamorelin	Five-residue peptide acting on the ghrelin (GHS) receptor

The "-morelin" ending is a shared naming stem and does not indicate receptor class, which is why ipamorelin and tesamorelin act on different receptors, as discussed in ipamorelin versus tesamorelin.

Which CAS number and formula should match?

The product listing gives CAS 901758-09-6, C223H370N72O69S and 5195.908 g/mol, which are acetate-form figures. The parent peptide, C221H366N72O67S at about 5135.9 g/mol, is typically indexed under CAS 218949-48-5. Two registry numbers for one active peptide is normal for salt forms, so confirm which form your COA states.

What should mass spectrometry show?

Electrospray MS observes the peptide ions, not the acetate counter-ion, so the deconvoluted mass should sit near 5135.9 Da even when the label lists 5195.9. Expected multiply charged ions (average mass, approximate):

Charge state	Approximate m/z
[M+4H]4+	1285.0
[M+5H]5+	1028.2
[M+6H]6+	857.0
[M+7H]7+	734.7
[M+8H]8+	643.0

A species near 5039.7 Da indicates peptide lacking the hexenoyl cap (loss of about 96.1 Da), and +16 Da indicates methionine oxidation. The general method is explained in mass spectrometry for peptide identity confirmation.

Related research guides

Research-use note

All materials discussed are supplied for in vitro laboratory research use only, and are not for human or animal use.

Frequently asked questions

What is tesa peptide?

Tesa is informal shorthand for tesamorelin, a 44-residue trans-3-hexenoyl GRF(1-44) analog studied in vitro as a GHRH-receptor agonist. View Tesamorelin

Is tesa the same as tesofensine?

No. Tesofensine is a small-molecule monoamine reuptake inhibitor, while tesamorelin is a 44-residue peptide.

Which CAS number identifies tesamorelin?

The product listing gives 901758-09-6 for the acetate-form material, while the parent peptide is typically indexed under 218949-48-5; confirm which form the batch COA states. Tesamorelin research profile

What mass should mass spectrometry show?

A deconvoluted mass near 5135.9 Da for the peptide, since the acetate counter-ion is not observed; about 5039.7 Da would indicate loss of the hexenoyl cap. Mass spectrometry for identity

Is it for human or animal use?

No. It is supplied for in vitro laboratory research use only.