Why is it called BPC-157?

BPC stands for Body Protection Compound, after the protective protein in human gastric juice it derives from. The 157 designates the specific 15-amino-acid partial sequence that was isolated and studied.

What does the -Cu in GHK-Cu mean?

It indicates a bound copper ion. GHK is the peptide sequence — glycine, histidine, lysine — and Cu is the chemical symbol for copper. The copper binding is central to how the complex is studied, so the name records it.

What do the numbers in brackets mean, as in ACTH(4–7)?

They give the amino acid positions taken from a larger parent molecule. ACTH(4–7) means residues four through seven of adrenocorticotropic hormone — the fragment Semax is based on.

Why does the same peptide have several different names?

Because compounds acquire names at different stages. A molecule may carry a developer’s lab code, then a generic name on approval, then a brand name — so PT-141, bremelanotide and Vyleesi all refer to the same molecule. Research literature and product labelling often use different ones.

Does the name tell you how well studied a compound is?

Not directly, though a generic or trade name usually indicates a compound has progressed through formal development, since those names are assigned during approval. A bare lab code says nothing either way about the size of the evidence base.

Research Library›Foundations›How Peptides Are Named

Reference

How Peptides Are Named: Decoding BPC-157, GHK-Cu, PE-22-28 and the Rest

Peptide names look like random codes until you know the handful of conventions behind them. Most are one of five things: a description, a sequence, a fragment, a lab code, or a trade name.

6 min read·3 studies cited·Updated July 2026

Quick Reference

Descriptive	Named for what it does — BPC-157, DSIP
Sequence	Named for its amino acids — GHK-Cu, KPV
Fragment	Named for its parent and position — ACTH(4–7)
Lab code	Developer’s internal designation — CJC-1295
Trade name	The approved-product name — Vyleesi, Scenesse

Why the Name Tells You Something

Peptide names are not arbitrary. Once you can spot which convention a name follows, it often tells you what the compound is, where it came from, or which part of a larger molecule it represents — before you read a word of the research.

Peptide names, in plain language: they work rather like surnames once did. Some surnames described a job — Smith, Baker, Fletcher — and that is BPC-157 or DSIP, named for what the compound is or does. Some are simply a list of who the parents were, and that is GHK-Cu or KPV, spelling out the amino acids themselves letter by letter. Some record where you came from, like ACTH(4–7), which names the parent molecule and the exact stretch of it that was taken. Some are nothing but a serial number a company happened to assign — CJC-1295, PT-141 — carrying no meaning whatsoever. And some are the name given later, on formal approval, the way a title differs from a birth name: PT-141 becomes Vyleesi. Learn which of the five you are looking at and the name stops being a code and starts being information.

There are five common conventions, and most compounds in this library follow one of them.

1. Descriptive: Named for What It Does

The most readable convention. The name is an abbreviation of a description, usually of the compound’s origin or observed activity.

BPC-157 stands for Body Protection Compound — a protective protein identified in human gastric juice — and the 157 designates the particular fragment of it that was isolated, a chain of fifteen amino acids. DSIP is simply Delta Sleep-Inducing Peptide, named for the delta-wave sleep activity observed when it was first isolated from rabbit brain in 1977. MOTS-c stands for Mitochondrial Open Reading Frame of the 12S rRNA type-c — dense, but it precisely locates where the peptide is encoded.

2. Sequence: Named for Its Amino Acids

Short peptides are often named by simply listing their amino acids, using the standard single-letter codes. This is the most literal convention of all — the name is the molecule.

GHK-Cu is glycine-histidine-lysine (G-H-K) bound to copper (Cu). KPV is lysine-proline-valine, the three-amino-acid tail of a larger hormone. Epitalon is frequently written as AEDG — alanine, glutamic acid, aspartic acid, glycine — and Pinealon as EDR.

A quick way to read these: if a peptide name is three or four capital letters with no obvious meaning, it is almost certainly the sequence itself. A trailing element symbol such as -Cu indicates a bound metal ion, which is often central to how the compound works.

3. Fragment: Named for Parent and Position

Many research peptides are pieces of larger molecules, and the name records exactly which piece, using bracketed numbers for the amino acid positions.

Semax is based on ACTH(4–7) — amino acids four through seven of adrenocorticotropic hormone. That notation is doing real work: it tells you the fragment retains the neuroactive portion while leaving behind the part that drives cortisol release. TB-500 relates to Thymosin Beta-4, and AOD-9604 is a modified fragment of the C-terminus of human growth hormone — the "AOD" standing for Anti-Obesity Drug, from its development programme.

PE-22-28 follows the same logic: a shortened analogue of Spadin, with the numbers marking the residue positions retained.

4. Lab Code: The Developer’s Designation

Some names are internal compound codes that stuck. They carry no descriptive meaning at all — they are simply what the developing organisation called the molecule.

CJC-1295 is a ConjuChem compound number. PT-141 is a Palatin Technologies designation. SS-31 comes from the initials of the researchers who characterised it — Szeto and Schiller. LL-37 is a hybrid: the LL refers to the two leucine residues at its start, and 37 to its total length.

These names tell you nothing about mechanism, which is exactly why they are so often mistaken for something more meaningful.

5. Trade Name: The Approved Product

When a compound reaches regulatory approval it gains a generic drug name and usually a brand name — so the same molecule can appear under three different labels depending on the source.

PT-141 becomes bremelanotide, sold as Vyleesi. Melanotan 1 becomes afamelanotide, sold as Scenesse. SS-31 is also called elamipretide in clinical literature.

This is worth stating plainly: an approval attaches to the finished pharmaceutical product under its trade name, not to the molecule in the abstract. A research-grade compound bearing the original lab code is not the approved medicine, however closely the two are related. Research-grade compounds are research materials only and are not approved by the TGA for human or veterinary use.

Why this causes the most confusion: a single molecule may appear under a research code, a generic name and a brand name in three different papers, giving the impression of three separate compounds.

It also matters for regulatory claims: an approval applies to the approved pharmaceutical product under its trade name, not to a research-grade compound bearing the original lab code.

Frequently Asked Questions

Compiled by the Southern Pacific Labs research team. Last updated July 2026.

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Published References

. “IUPAC-IUB Joint Commission on Biochemical Nomenclature (JCBN). Nomenclature and symbolism for amino acids and peptides. Recommendations 1983.” European journal of biochemistry, 1984. PubMed
A 1993 correction is recorded. The official online recommendations incorporate published corrections and are available through the link below. The separate 1993 notice has not been reviewed in full here. View notice
World Health Organization. “Guidance on the use of International Nonproprietary Names (INNs) for pharmaceutical substances.” WHO Programme on INN, 2017. Source
Nelson DL, Cox MM, Hoskins A. “Lehninger Principles of Biochemistry (Chapter 3: Amino Acids, Peptides, and Proteins).” W. H. Freeman, 8th ed., 2021. Source