A pentadecapeptide is a peptide composed of fifteen amino acids. The term combines the Greek “penta-deca” (fifteen) with “peptide,” and it is a precise classification within the broader system used to describe peptides by their amino acid count. The best-known pentadecapeptide in research is BPC-157 — often referred to as “stable gastric pentadecapeptide BPC 157” in the published literature, where the word pentadecapeptide appears directly in the compound’s formal description. This guide explains what a pentadecapeptide is, where the term sits within peptide nomenclature, why the length of a peptide matters, and why BPC-157 is described this way.
Peptide length terminology
| Term | Number of amino acids | Example |
|---|---|---|
| Dipeptide | 2 | Carnosine |
| Tripeptide | 3 | GHK, KPV |
| Pentapeptide | 5 | Ipamorelin |
| Heptapeptide | 7 | Melanotan 2 |
| Octapeptide | 8 | TB-500 |
| Pentadecapeptide | 15 | BPC-157 |
| Polypeptide | Many (often >20–50) | Larger peptides and small proteins |
What “pentadecapeptide” means
Peptides are chains of amino acids linked by peptide bonds. The number of amino acids in the chain is one of the most basic ways to classify a peptide, and a standardised naming system exists that uses Greek numerical prefixes to indicate the count. A pentadecapeptide sits at fifteen amino acids — “penta” (five) plus “deca” (ten).
This places it among the small-to-medium peptides. It is substantially larger than the tripeptides (three amino acids, such as GHK-Cu or KPV) and pentapeptides (five amino acids, such as Ipamorelin) common in peptide research, but far smaller than the polypeptides and proteins that contain dozens or hundreds of residues. At fifteen amino acids, a pentadecapeptide is large enough to fold into a defined structure and present a specific biological activity, while remaining small enough to be manufactured by standard solid-phase peptide synthesis.
Why peptide length matters
The number of amino acids in a peptide is not merely a labelling convention — length has real consequences for how a peptide behaves.
Structure and activity
Length influences how a peptide folds and what three-dimensional shape it can adopt. Very short peptides (di- and tripeptides) are usually too small to form stable folded structures and tend to act through direct chemical interactions or as fragments of larger molecules. Longer peptides can fold into defined conformations that present specific binding surfaces. At fifteen amino acids, a pentadecapeptide can adopt a defined active conformation, which is part of what allows a molecule like BPC-157 to have a specific and reproducible biological profile.
Stability
Length and sequence together determine how resistant a peptide is to enzymatic degradation. Some peptides are rapidly broken down by proteases; others are unusually stable. BPC-157 is notable in the published literature precisely because it is described as a stable pentadecapeptide — its particular fifteen-amino-acid sequence confers resistance to degradation, including reported stability in gastric environments where many peptides would be rapidly broken down.
Manufacturing
Peptide length affects how a peptide is produced and how purity is assessed. Solid-phase peptide synthesis builds a peptide one amino acid at a time, and each coupling step has the potential to introduce impurities such as truncated sequences (where a residue was missed). Longer peptides have more coupling steps and therefore more opportunities for synthesis-related impurities, which is one reason HPLC purity verification is important regardless of peptide length. For more on purity assessment, see our guide on understanding peptide purity.
BPC-157: the reference pentadecapeptide
BPC-157 is the pentadecapeptide most researchers encounter, and the term appears directly in its formal description throughout the published literature, where it is routinely called “stable gastric pentadecapeptide BPC 157.”
Its fifteen-amino-acid sequence (Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val) is derived from a partial sequence of a protective protein originally identified in gastric juice. The “stable” descriptor is significant: it reflects the peptide’s documented resistance to degradation, which distinguishes it from many other small peptides and is part of why it has been studied so extensively in tissue research. The pentadecapeptide classification, the specific sequence, and the stability are all interconnected — it is this particular fifteen-residue arrangement that produces the stability and the biological profile described in the research.
For a comprehensive overview of BPC-157 — including mechanism of action, published research, pharmacokinetics, and handling — see our BPC-157 research guide.
Frequently asked questions
What is a pentadecapeptide?
A pentadecapeptide is a peptide made up of fifteen amino acids. The name comes from the Greek prefixes “penta” (five) and “deca” (ten). It sits within the standard system of naming peptides by their amino acid count.
Is BPC-157 a pentadecapeptide?
Yes. BPC-157 is a pentadecapeptide — it consists of fifteen amino acids. In published research it is formally described as “stable gastric pentadecapeptide BPC 157,” with the term appearing directly in its name.
How many amino acids are in a pentadecapeptide?
Fifteen. For comparison, a tripeptide has three (e.g. GHK-Cu, KPV), a pentapeptide has five (e.g. Ipamorelin), and an octapeptide has eight (e.g. TB-500).
Why does peptide length matter?
Length affects how a peptide folds and what activity it can have, how stable it is against enzymatic degradation, and how it is manufactured and purity-tested. At fifteen amino acids, a pentadecapeptide is large enough to adopt a defined active conformation while remaining small enough for standard solid-phase synthesis.
What does “stable” mean in “stable pentadecapeptide”?
It refers to BPC-157’s documented resistance to degradation. Its particular fifteen-amino-acid sequence makes it more resistant to breakdown than many other small peptides, including reported stability in gastric environments. The stability is a property of the specific sequence, not of pentadecapeptides in general.
Can BPC-157 be used in humans?
No. Trutide research products are supplied strictly for in vitro laboratory and scientific research. They are not for human or veterinary use, clinical use, self-administration, diagnosis, treatment or prevention of disease.
Further reading
For a full overview of the reference pentadecapeptide — including mechanism of action, published research, pharmacokinetics, and handling — see our BPC-157 research guide.
Research use only. This article is provided for laboratory and scientific reference purposes. Trutide research products are supplied strictly for in vitro laboratory research and are not for human or veterinary use, clinical use, self-administration, diagnosis, treatment or prevention of disease.
References
- Sikiric P, Seiwerth S, Rucman R, et al. Stable gastric pentadecapeptide BPC 157: novel therapy in gastrointestinal tract. Current Pharmaceutical Design. 2011;17(16):1612-1632. doi:10.2174/138161211796196954
- Sikiric P, Seiwerth S, Rucman R, et al. Brain-gut axis and pentadecapeptide BPC 157: theoretical and practical implications. Current Neuropharmacology. 2016;14(8):857-865. doi:10.2174/1570159X13666160502153022
- Merrifield RB. Solid phase peptide synthesis. I. The synthesis of a tetrapeptide. Journal of the American Chemical Society. 1963;85(14):2149-2154. doi:10.1021/ja00897a025
- Sikiric P, Rucman R, Turkovic B, et al. Novel cytoprotective mediator, stable gastric pentadecapeptide BPC 157. Vascular recruitment and gastrointestinal tract healing. Current Pharmaceutical Design. 2018;24(18):1990-2001. doi:10.2174/1381612824666180608109141
Last updated: 7 June 2026