BPC-157 and TB-500 are two synthetic peptides frequently cataloged side by side in laboratory research settings, yet they are structurally distinct molecules from different sequence origins. This comparison examines them strictly as research materials — by classification, peptide length and class, molecular profile, and physical format — and makes no reference to biological effects, outcomes, or administration.
BPC-157 is a 15-residue pentadecapeptide derived from a partial sequence of a gastric protein, while TB-500 corresponds to a 44-residue fragment associated with the actin-binding protein thymosin beta-4. All molecular values below are drawn only from documented analytical data for each compound; the material is intended for in-vitro and laboratory research use only and is not for human or veterinary use.
Classification. Both compounds are classified as synthetic peptides supplied as research chemicals. BPC-157 (CAS 137525-51-0), also referenced as Body Protection Compound-157, Pentadecapeptide BPC 157, PL 14736, or Bepecin, is a stand-alone pentadecapeptide sequence not found as a contiguous natural protein. TB-500 (CAS 77591-33-4) is the synthetic acetate form of a fragment associated with thymosin beta-4 (Tβ4), studied in tissue-repair and actin-regulation research contexts. Neither is a small-molecule drug; both are amino-acid polymers characterized by sequence and mass.
Peptide structure and class. The two differ substantially in length and complexity. BPC-157 is a linear 15-amino-acid peptide with the sequence H-Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val-OH, notable for a proline-rich central motif and free N- and C-termini. TB-500 is a longer linear 44-amino-acid peptide, N-terminally acetylated (Ac-Ser-Asp-Lys-Pro-...-Gly-Glu-Ser), placing it in a higher molecular-size class. The acetyl cap on TB-500 and the free glycine N-terminus on BPC-157 represent distinct terminal chemistries relevant to synthesis and analytical identity.
Molecular profile. BPC-157 has the molecular formula C62H98N16O22 and a molecular weight of approximately 1419.53 g/mol. TB-500 carries the formula C212H350N56O78S with a molecular weight near 4963.44 g/mol — roughly three and a half times the mass of BPC-157 — and its single sulfur atom (from a methionine residue) distinguishes its elemental composition; BPC-157 contains no sulfur. Both are typically specified at high chromatographic purity (≥ 99% by HPLC/MS) on lot documentation.
Physical format. In their catalog form, both are generally supplied as sterile-filtered, lyophilized (freeze-dried) white powders sealed in vials, requiring reconstitution with a suitable solvent before laboratory handling. Their reconstitution chemistry differs mainly by molecular size and residue makeup rather than by procedure, and both are specified for cool, desiccated storage to preserve peptide stability. Each ships with third-party analytical documentation identifying lot, purity, and mass.
Frequently asked questions
Are BPC-157 and TB-500 the same class of compound?
Both are synthetic research peptides, but they are structurally different. BPC-157 is a 15-residue pentadecapeptide, while TB-500 is a 44-residue acetylated fragment associated with thymosin beta-4. They share the peptide classification but not sequence, length, or origin.
How do their molecular weights compare?
BPC-157 has a molecular weight of about 1419.53 g/mol (formula C62H98N16O22). TB-500 is considerably larger at approximately 4963.44 g/mol (formula C212H350N56O78S), reflecting its 44-amino-acid chain versus BPC-157's 15 residues.
What is the key structural difference in their sequences?
BPC-157 is a short, proline-rich linear peptide with free N- and C-termini. TB-500 is a longer linear peptide that is N-terminally acetylated and contains a methionine residue, giving it a single sulfur atom that BPC-157's formula lacks.
What physical form are these research compounds supplied in?
Both are typically provided as lyophilized (freeze-dried) powders in sealed vials, requiring reconstitution with an appropriate solvent for laboratory use. Each is specified for cool, desiccated storage and ships with third-party HPLC/MS documentation.
Are these products intended for human or veterinary use?
No. Both BPC-157 and TB-500 are offered strictly as research chemicals for in-vitro and laboratory research use only. This comparison addresses analytical and structural properties and makes no claims of biological effect.
Compare the data, then verify it.
Every compound above ships lot-tested with third-party HPLC/MS documentation.
This comparison covers analytical and structural properties for laboratory research use only. It is not medical advice and makes no claims of effect; products are not for human or veterinary consumption.
