Wolverine Stack (BPC-157 & TB-500) | 20mg

BPC-157 and TB-500 Research Compound Set — listed here as the "Wolverine Stack" — is a two-peptide research preparation that combines a synthetic pentadecapeptide (BPC-157) and a beta-thymosin fragment (TB-500) in equal proportion in a single 20mg vial, supplied ready-mixed in solution rather than as a lyophilized cake awaiting reconstitution. Material in this catalogue is synthesized in the UK.

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Two unrelated molecules sharing one vial

The pairing is a commercial convention, not a chemical relationship. BPC-157 is a 15-residue peptide, sequence GEPPPGKPADDAGLV, corresponding to a partial sequence of a protein identified in gastric juice; average mass is about 1,419 Da. It is unusually proline-rich — four prolines in fifteen residues — which constrains its backbone, and it contains no cysteine, so there is no disulfide to form, scramble, or misassign.

TB-500 belongs to a different family entirely. Thymosin beta-4 is a 43-residue protein of roughly 4.9 kDa. TB-500, as the name is used across catalogues, is a fragment built around the actin-binding motif LKKTETQ, not the intact protein — a distinction the name itself does not make explicit. The mass gap between fragment and full-length protein is several kilodaltons, so mass spectrometry settles the question immediately. Any supplier's identity data should tell you which molecule is actually in the vial.

The two also differ in net charge near neutral pH: BPC-157 carries a glutamate and two aspartates against a single lysine and reads net anionic, while the TB-500 fragment — two lysines against one glutamate and a free C-terminal carboxylate, with its N-terminus acetylated — sits close to neutral. That difference is useful rather than problematic — it is part of what lets an analyst pull the two apart.

Analytical consequences a buyer should hold suppliers to

Because the components differ in both hydrophobicity and charge, reversed-phase HPLC and ion-exchange are both capable of resolving them. A co-formulated set should therefore be characterized as two peaks with a stated area ratio, not as a single purity figure. One number for a two-component preparation tells you nothing about whether the ratio in the vial matches the label.

A second point is easy to overlook: neither sequence contains tryptophan, tyrosine, or phenylalanine. Detection at 280 nm — a common default wavelength on UV setups — is effectively blind to both molecules. Purity chromatograms must be run near 214 nm, where the peptide bond itself absorbs. If a document shows a 280 nm trace for either compound, it is not evidence of anything.

Degradation chemistry follows from the same sequences. With no methionine and no cysteine in either component, oxidation and disulfide scrambling are not the leading failure routes. What is worth watching is aspartate chemistry in BPC-157 — it carries two adjacent aspartates, and Asp-containing sequences are prone to isomerization through a succinimide intermediate — and glutamine deamidation in the TB-500 fragment, which presents as a roughly +1 Da mass shift and often an extra shoulder on the main peak. Those are the signatures a stability-indicating method should be able to see.

Pre-mixed solution versus lyophilized powder

Peptide material reaches a bench in one of two formats: a lyophilized powder to be reconstituted, or a solution formulated at fill. The trade-offs run in both directions:

A pre-configured format removes the variability that comes with preparing and combining solutions in-house, which is the whole point of a set like this one: the composition is standardized before it reaches the bench. The cost is that a solution has no dry-state grace period, so the honest questions to put to any vendor of a liquid format are what the formulation medium is, what the fill date was, and what stability evidence sits behind the format. Short, unstructured peptides without oxidation-labile residues are among the better candidates for a solution presentation, but that is an argument for asking the question, not for skipping it.

Reading a Certificate of Analysis properly

Whoever you buy from, a Certificate of Analysis is only useful if you read past the headline percentage:

• Identity by mass spectrometry — observed mass against theoretical, for each component, not just one.
• Purity by RP-HPLC at ~214 nm, with the chromatogram attached rather than a bare number.
• Net peptide content as distinct from chromatographic purity. Purity says what fraction of the peptide is the right peptide; net content accounts for counterion and water, which are not peptide.
• Counterion identity — acetate and trifluoroacetate behave differently in downstream assays, and TFA carryover from purification is a known confounder in cell work.
• Batch traceability — a lot number that actually appears on the vial, an analysis date, and a named laboratory. An undated, unattributed document is decoration.

Our published documents for the compounds that have them are collected at /coa.

Storage and handling

Treat the material as you would any peptide in solution: cold, dark, sealed, and protected from repeated freeze–thaw cycling. Splitting the contents into small aliquots on receipt is the standard way to avoid warming a whole container repeatedly. Label aliquots with the lot number so any anomaly later can be traced back to a batch.

The published literature

Both molecules sit behind a body of in-vitro and animal laboratory research under examination, concerned in part with cell migration and cytoskeletal behavior in model systems. It is a body of research under investigation, not a set of established findings, and no conclusions are drawn from it here.

BPC-157 and TB-500 (a thymosin beta-4 fragment) both appear on the WADA Prohibited List.

Related listings

The components are also catalogued individually as BPC-157 and TB-500. Other pre-configured multi-peptide sets in this range include the Glow Stack and the KLOW Stack, which are built on entirely different compounds and are not substitutes for this one.