What are BPC-157 and TB-500? Molecular identity and batch verification
Among research peptides, few combinations draw as many questions as BPC-157 and TB-500. They are structurally distinct molecules, each with its own published literature and a separate analytical profile. This article covers only what the published record says about each: what it is, how it is characterized, and what working with the combination means in practice.
BPC-157: a gastric-derived pentadecapeptide
BPC-157 stands for Body Protection Compound 157. It is a synthetic peptide of 15 amino acids with a molecular weight of approximately 1,419.5 Da. In literature and catalogs it also appears as bpc157 (no hyphen), the compact spelling of the same peptide. The full sequence is listed further down in the structural-differences table.
The Zagreb research group, led by Sikirić and collaborators, described the BPC peptide for the first time in 1993 in the Journal of Physiology, Paris, presenting evidence for a new peptide isolated from human gastric juice. That same year, in a paper in Life Sciences, the authors used the name "BPC 157, a 15 amino acid peptide BPC fragment" to refer to the compound in studies using in vivo models of gastric and duodenal injury.
The compact size of BPC-157 makes analytical verification straightforward. Mass spectrometry (MS) confirms the exact molecular weight of the intact peptide. Reversed-phase HPLC (RP-HPLC) quantifies purity: for research-grade material the main peak should account for at least 95% of the total chromatogram area, with the remainder corresponding to identified synthesis impurities. The per-batch Certificate of Analysis (COA) documents both measurements alongside the unique batch number that allows tracing the origin of the material.
TB-500: a synthetic peptide related to thymosin beta-4
Thymosin beta-4 (Tβ4) is a 43-amino-acid protein with a molecular weight of approximately 4,921 Da, originally identified in thymic tissue. Its complete bovine sequence was reported by Low, Hu, and Goldstein in 1981 in the Proceedings of the National Academy of Sciences, where the authors described the peptide and characterized its activity in thymic tissue.
In 1993, Hannappel and Wartenberg published in Biological Chemistry Hoppe-Seyler a study that identified which regions of Tβ4 bind to actin, the protein that forms part of the cell's internal scaffolding. That region (called the LKKTET motif) is one of the sequence's identity markers and shows up in the analytical profile documenting a batch.
TB-500 is the name the research market uses for the synthetic form of thymosin beta-4, or its active fractions, in lyophilized presentations. Because the chain is longer than BPC-157, analytical verification is more demanding. During synthesis it is easier for impurities to appear, and all of them must be separated and identified by HPLC before the batch can be released. MS confirms the full-molecule weight and RP-HPLC quantifies purity against those process impurities.
The combination: two molecules, one combined COA is not enough
Combining BPC-157 and TB-500 in a single lyophilized vial is a standard presentation in the research market. The analytical challenge of this combination is that the COA must certify the identity and purity of each component independently. A single chromatogram of the mixture, without individual peak identification, does not allow determining whether the reported purity corresponds to both molecules or only to the dominant one by concentration.
A complete COA for this combination includes: MS-confirmed molecular weight for each peptide, RP-HPLC purity for each component with identified peaks, a unique batch number, and a referenced analytical method. The guide on how to read a peptide COA covers each field in that document.
When working with the combination in the lab, calculating the concentration of each component at reconstitution is a critical step: the total lyophilized weight is split between the two peptides according to the formulation stated in the COA. The Égida peptide calculator and the guide on how to calculate peptide concentration cover that step in detail.
The BPC-157 + TB-500 combination from Égida is available as a research-grade lyophilized vial with a per-batch COA and HPLC-verified purity. The 5/5 mg vial is currently $1,200 MXN; you can add it to the cart directly from the product page. The batch COA is shared once you confirm the order, with discreet shipping throughout Mexico.
Structural differences at a glance
- BPC-157: pentadecapeptide (15 aa), sequence GEPPPGKPADDAGLV, mass ~1,419.5 Da, derived from a gastric peptide, verified by MS and RP-HPLC.
- TB-500 (synthetic thymosin beta-4): 43-aa peptide (full form), mass ~4,921 Da, thymic origin, LKKTET motif in its sequence, verified by MS and RP-HPLC with particular attention to truncated and deamidated forms.
Both are synthetic research peptides that require a per-batch COA to certify identity and purity. That documentation is the first quality gate before any experimental use. The principles behind the purity metric are covered in our article on HPLC purity and why 99% matters.
FAQ
What does BPC-157 stand for?
BPC-157 stands for Body Protection Compound 157. It is a synthetic pentadecapeptide of 15 amino acids (sequence GEPPPGKPADDAGLV), derived from a fragment of the human gastric juice protein, with a molecular weight of approximately 1,419.5 Da.
Are bpc157 and BPC-157 the same thing?
Yes. bpc157 (no hyphen) is the compact spelling of the same peptide. Both forms refer to the same compound; the per-batch COA states its identity and purity regardless of which spelling is used.
What is TB-500 and how does it relate to thymosin beta-4?
TB-500 is the name the research market uses for the synthetic form of thymosin beta-4 (Tβ4), a 43-amino-acid peptide (~4,921 Da) originally identified in thymic tissue. It is the same molecule or a fraction of it synthesized for laboratory use.
How is BPC-157 + TB-500 combination purity verified?
The per-batch COA must include MS-confirmed molecular weight for each peptide and reversed-phase HPLC purity for each component individually. A chromatogram that groups both peptides without identifying individual peaks does not allow independent purity verification for each compound.
Why are BPC-157 and TB-500 studied together?
They are structurally distinct molecules that research literature has frequently studied in related contexts. This combined presentation facilitates laboratory work, but analytically each peptide must be verified independently.
Sources
- Sikirić P, Petek M, Rucman R, Seiwerth S, Grabarević Z, Rotkvić I, Turković B, Jagić V, Mildner B, Duvnjak M. A new gastric juice peptide, BPC. An overview of the stomach-stress-organoprotection hypothesis and beneficial effects of BPC. J Physiol Paris. 1993;87(5):313–327. PMID 8298609.
- Sikiric P, Seiwerth S, Grabarevic Z, Petek M, Rucman R, Turkovic B, Rotkvic I, Jagic V, Duvnjak M, Mise S. The beneficial effect of BPC 157, a 15 amino acid peptide BPC fragment, on gastric and duodenal lesions induced by restraint stress, cysteamine and 96% ethanol in rats. A comparative study with H2 receptor antagonists, dopamine promotors and gut peptides. Life Sciences. 1994;54(5):PL63–PL68. PMID 7904712.
- Low TL, Hu SK, Goldstein AL. Complete amino acid sequence of bovine thymosin beta 4: a thymic hormone that induces terminal deoxynucleotidyl transferase activity in thymocyte populations. Proc Natl Acad Sci USA. 1981;78(2):1162–1166. PMID 6940133.
- Hannappel E, Wartenberg F. Actin-sequestering ability of thymosin beta 4, thymosin beta 4 fragments, and thymosin beta 4-like peptides as assessed by the DNase I inhibition assay. Biol Chem Hoppe Seyler. 1993;374(2):117–122. PMID 8471179.