Peptide identity index
The peptide identity index tells you whether two names used for research peptides refer to the same molecule. Look up a catalog name, a CAS number, or an alias. Compare a second name when a vial, a paper, or a COA uses a different label.
Mass values computed from sequence are for checking an HPLC-MS report. This page does not calculate reconstitution volumes or human doses. Pair it with a lot-linked Certificate of Analysis and the 12-point COA audit.
Often confused pairs
These are the name collisions that show up in papers, forums, and supplier tables.
TB-500 vs thymosin beta-4
Fragment versus the 43-residue protein. Same family, not the same molecule.
Semax vs Adamax
Adamax is N-acetyl Semax amidate. Extra caps on both termini.
HGH 191aa vs AOD-9604
Full-length somatropin versus a modified C-terminal fragment.
CJC-1295 with DAC vs without
Drug-affinity complex changes mass, clearance, and the CAS number.
Semaglutide vs tirzepatide
GLP-1 analog versus a GIP/GLP-1 dual agonist. Different sequences.
Melanotan 1 vs 2
Linear tridecapeptide versus a shorter cyclic analog.
MGF vs PEG-MGF
Same IGF-1 Ec stretch. PEGylation makes the mass variable.
BPC-157 vs TB-500
Fifteen residues versus seven. Often ordered together, never interchangeable.
Selank vs Semax
Both are heptapeptides with a PGP tail. Different N-terminal sequences.
Pinealon vs epithalon
EDR versus AEDG. Short Khavinson peptides, not the same residue set.
How the index decides
Catalog CAS, formula, and sequence come from Tetrava lot identity tables. Monoisotopic mass and expected ions are calculated only when the sequence parses as standard residues plus common caps (acetyl, amide, Aib, Nle, pGlu). Heavily modified GLP-1 analogs stay as catalog text.
TB-500 is the main trap. Supplier tables often reuse the CAS and 4,963 Da mass of full-length thymosin beta-4 on a vial whose sequence is Ac-LKKTETQ. This index splits those identities on purpose.
Research use only. Not for human or veterinary consumption.