What Is BPC-157? Peptide Class, Sequence, and Reconstitution

Key takeaways

• BPC-157 is a synthetic pentadecapeptide: a single chain of 15 amino-acid residues with no disulfide bonds or post-translational modifications.
• Its sequence is Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val, and it is derived from a partial sequence reported in gastric juice protein.
• The free-base molecular formula is commonly given as C62H98N16O22 with an average molecular weight near 1419.5 g/mol; it is frequently supplied as an acetate salt, which raises the as-weighed mass per vial.
• Research vials ship lyophilized and are reconstituted with bacteriostatic or sterile water; concentration is simply labeled peptide mass divided by the volume of diluent added.
• Ascend Bio Labs supplies BPC-157 with a public, per-batch COA keyed to the batch ID on each vial, with independent third-party HPLC for purity and LC-MS for identity, all US-domestic.

BPC-157 is one of the most widely catalogued research peptides, and also one of the most loosely described. This guide stays strictly structural: it covers what kind of molecule BPC-157 is, the amino-acid sequence that defines it, how its molecular formula and weight are calculated, the salt form you are likely to receive, and the mechanics of reconstituting and storing a lyophilized research vial. Nothing here addresses what the compound does in any organism it is written for laboratory handling and characterization only.

Understanding the structure is also what lets you read a certificate of analysis for the material. The sequence fixes the theoretical mass that LC-MS should confirm; the salt form changes the net peptide content per vial; and the lyophilized presentation dictates how reconstitution math works. Each section below ties a structural fact to the practical handling consequence that follows from it.

Peptide class: a synthetic pentadecapeptide

BPC-157 belongs to the peptide class by the plain definition of the term: it is a short chain of amino acids joined by peptide bonds, far below the length at which a chain is conventionally called a protein. Specifically it is a pentadecapeptide a chain of fifteen residues. The 'penta-deca' prefix simply counts the residues (five plus ten), and the count is the single most defining structural fact about the molecule.

Structurally it is a linear, single-chain peptide. It carries no cysteine residues, so there are no disulfide bridges to form, and it has no glycosylation, phosphorylation, lipidation, or other post-translational modifications in the synthetic research material it is the bare amino-acid sequence. That simplicity is part of why it is straightforward to synthesize by solid-phase peptide synthesis and to characterize by chromatography and mass spectrometry.

The name itself is an abbreviation: BPC stands for 'body protection compound', and BPC-157 refers to a specific 15-residue partial sequence that was reported as a fragment of a larger protein found in gastric juice. In a research-catalogue context, treat 'BPC-157' as a label for that defined fifteen-residue sequence rather than as a description of any biological role.

• Class: peptide, specifically a pentadecapeptide (15 residues).
• Topology: linear single chain, no disulfide bonds.
• No glycosylation or other post-translational modifications in the synthetic material.
• 'BPC-157' denotes a defined 15-residue partial sequence, not a function.

The sequence: fifteen residues, three prolines in a row

The defining feature of any peptide is its primary sequence the ordered list of amino acids. For BPC-157 the sequence is commonly written, N-terminus to C-terminus, as Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val. In single-letter code that is GEPPPGKPADDAGLV. Reading it left to right gives you the order in which the residues are assembled and the order a synthesis log or a sequencing readout will reference.

A few features of the sequence are worth noting because they affect both synthesis and the molecular formula. There are three consecutive proline residues (the Pro-Pro-Pro stretch near the N-terminus) plus a fourth proline later in the chain; prolines constrain the backbone and are a recognizable structural signature of this peptide. There are also two adjacent aspartate residues (Asp-Asp), and a single lysine. The composition four prolines, two aspartates, two glycines beyond the termini, and so on is what determines the atom count when you tally the formula.

The sequence is what a mass-spectrometry identity check is really validating. When an LC-MS report states an observed mass consistent with the theoretical mass, it is asserting that the assembled chain matches this exact residue order and composition. A clean purity peak with the wrong mass would indicate a pure but incorrect molecule which is why identity and purity are reported as two separate measurements on a complete certificate.

Molecular formula and weight, and why the salt form matters

Summing the residues of the free-base (non-salt) peptide gives a molecular formula commonly cited as C62H98N16O22. The corresponding average molecular weight is approximately 1419.5 g/mol, with the monoisotopic mass slightly lower; you will see small rounding differences between sources depending on whether average or monoisotopic mass is quoted and how termini are counted. For research characterization, the figure that matters is that the observed mass on an LC-MS readout should land on the theoretical mass for this formula within instrument tolerance.

The salt form is the most common source of confusion about 'how much peptide is in the vial'. BPC-157 is frequently supplied as an acetate salt, because the trifluoroacetate or acetate counterions used in purification and lyophilization remain associated with the basic residues. An acetate salt weighs more than the free base for the same number of peptide molecules, so a vial labeled by gross fill weight contains slightly less net peptide than the free-base molecular weight alone would suggest. A rigorous COA may report net peptide content (active weight) separately from gross fill, which is why some vendors emphasize 'active weight content' on their certificates.

For reconstitution math (next section) this matters only if you are working from net peptide content; if you simply use the labeled peptide mass printed for the vial, the salt is already accounted for. The structural takeaway is that the molecular weight you calculate from the sequence describes the free base, while the powder you weigh out is typically a salt.

• Free-base molecular formula: commonly C62H98N16O22.
• Average molecular weight: approximately 1419.5 g/mol (monoisotopic slightly lower).
• Often supplied as an acetate salt, raising as-weighed mass per vial.
• Net peptide content (active weight) can differ from gross fill weight.

The lyophilized vial: what you actually receive

Research BPC-157 ships as a lyophilized (freeze-dried) powder or thin cake in a sealed vial, typically under an inert headspace. Lyophilization removes water from the frozen peptide under vacuum, leaving a dry solid that is far more stable in transit and storage than a solution would be. The visible amount of cake can look surprisingly small a few milligrams of peptide occupy very little volume so do not judge fill weight by eye.

Every vial should carry a label that ties it to its analytical paperwork: the compound name, the labeled peptide mass (fill), and a batch or lot ID. That batch ID is the link between the powder in front of you and the certificate of analysis for that production run, because purity and identity are properties of a specific run rather than of the product name in general. For a field-by-field walkthrough of that document, see How to Read a Peptide Certificate of Analysis (COA).

BPC-157 is also commonly offered in a co-formulated research vial alongside TB-500; if you are evaluating a blend rather than a single compound, the label should state the mass of each peptide in the vial separately. The structure and specifications of that pairing are covered in BPC-157 + TB-500 Blend: What the Combined Vial Contains, and the companion fragment's own structure in What Is TB-500? Thymosin Beta-4 Fragment Structure and Specs.

Reconstitution: turning labeled mass into a known concentration

Reconstitution is the step that converts a dry vial into a solution of known concentration for laboratory work. The diluent is typically bacteriostatic water (sterile water with a small amount of benzyl alcohol as a preservative) or plain sterile water; bacteriostatic water is common when a reconstituted vial will be drawn from more than once. The diluent is added slowly down the inner wall of the vial rather than directly onto the cake, and the vial is swirled, not shaken vigorously, until the powder fully dissolves.

The concentration that results is pure arithmetic: it is the labeled peptide mass divided by the volume of diluent you add. Adding 2 mL of water to a 5 mg vial yields 5 mg / 2 mL = 2.5 mg/mL; adding 1 mL to the same vial yields 5 mg/mL. The vial's peptide mass is fixed by what was filled and tested, so the only variable you control is the diluent volume, and that volume sets the concentration. Because the chosen volume drives the math, this peptide reconstitutes by exactly the same procedure as any other lyophilized research peptide for the full step-by-step volume calculation see Reconstituting Lyophilized Peptides: BAC Water Math Step by Step.

BPC-157's solubility behavior is unremarkable for a short, modestly polar peptide: it generally goes into aqueous diluent readily, helped by its charged aspartate and lysine residues. If a cake is slow to dissolve, additional gentle swirling and time at room temperature usually resolve it; the structural point is simply that this is a water-reconstituted lyophilizate, not an oil- or solvent-based preparation.

• Diluent: bacteriostatic water (multi-draw) or sterile water.
• Add diluent down the vial wall; swirl gently, do not shake hard.
• Concentration = labeled peptide mass ÷ diluent volume added.
• Example: 5 mg vial + 2 mL water = 2.5 mg/mL.

Storage: lyophilized versus reconstituted

Storage requirements differ sharply between the dry and the dissolved states. As a sealed lyophilized powder, BPC-157 is comparatively stable and is commonly stored refrigerated, with freezing used for longer-term holding; kept dry, cold, and away from light, a freeze-dried peptide cake is far more forgiving than a solution. The sealed inert headspace and the absence of water are what give the dry form its stability.

Once reconstituted, the peptide is in solution and should be treated as the more perishable form: kept refrigerated, protected from light, and used within a limited window. Repeated freeze-thaw cycling of a reconstituted vial is generally avoided because each cycle stresses the peptide; this is one reason bacteriostatic water is chosen for vials that will be sampled multiple times. None of this is a usage instruction it is ordinary cold-chain handling for a research reagent in solution.

Storage handling and COA both come back to the same principle: the material's identity and quality are established at the batch level and then preserved by correct handling. Ascend Bio Labs supplies BPC-157 with a public, per-batch certificate of analysis keyed to the unique batch ID printed on each vial, with independent third-party HPLC for purity and LC-MS for molecular identity, and US-domestic synthesis, testing, storage, and shipping with insulated, tracked transit so the dry vial that arrives is the one its certificate describes. For related single-compound structure guides, see What Is GHK-Cu? Copper-Binding Tripeptide Structure Explained.

• Lyophilized powder: store cold and dry, away from light; freeze for long-term holding.
• Reconstituted solution: refrigerate, protect from light, use within a limited window.
• Avoid repeated freeze-thaw cycles of a reconstituted vial.
• Batch ID on the vial links the material to its per-batch COA.

Related research notes

• What Is TB-500? Thymosin Beta-4 Fragment Structure and Specs
• What Is GHK-Cu? Copper-Binding Tripeptide Structure Explained
• BPC-157 + TB-500 Blend: What the Combined Vial Contains
• Reconstituting Lyophilized Peptides: BAC Water Math Step by Step