The Secret Code Hidden in Peptide Names
BPC-157, TB-500, sermorelin, semaglutide: what the numbers, letters and endings in peptide names mean, and what a name can never tell you.
In short
Most peptide names follow a few simple patterns. A number, as in BPC-157, is a lab label, not a strength or a dose. Some names, like TB-500, point to a bigger "parent" molecule. The ending "-relin" usually marks a peptide that tells the body to release a hormone, and "-tide" usually marks a peptide drug with an official name. A name can hint at what a molecule is and what it's meant to do. It can never tell you whether it works or whether it's safe.
- The number in a name like BPC-157 or TB-500 is a label, not a dose, a strength or a version.
- A short piece of a bigger molecule is not the same molecule, so research on thymosin beta-4 doesn't automatically apply to TB-500.
- Official drug names use shared endings. "-relin" means "release a hormone", "-morelin" means "release growth hormone", and "-tide" means "peptide drug".
- A peptide without an official name usually hasn't been through formal drug development, which is a reason to look harder at the evidence.
Peptide names can look like random codes: BPC-157, TB-500, sermorelin, semaglutide. They aren't random. Most names follow a handful of simple patterns, and once you know them you can get a rough idea of what a name means before you read anything else about it.
This guide covers four patterns. You don't need to memorize any chemistry. As always, we explain what names mean and what the research says. We don't recommend or sell anything, and we don't discuss dosing.
| Pattern | Example | What a name can hint at |
|---|---|---|
| 01 · A number | BPC-157 | A number is a label |
| 02 · A parent | TB-500 | Some names point to a parent |
| 03 · "-relin" | sermorelin | Release a hormone |
| 04 · "-tide" | semaglutide | A peptide drug |
Why are names worth reading?
In our last guide, we gave you four questions to ask about any peptide. A name is a shortcut into the first two. It can hint at what a molecule is and what it's meant to do.
- What is it made of? A name can hint at this.
- What does it bind to? A name can hint at this too.
- What happens next? Not in a name.
- What's the evidence? Not in a name.
But a hint is all it is. A name never tells you whether something works, whether it's safe, or whether a product contains what its label says.
What does the number in BPC-157 mean?
Take BPC-157. "BPC" stands for "Body Protection Compound", a nickname researchers gave it. "157" is part of its lab designation, like a catalog number 3.
It's a common mistake to read the number as a dose, a strength or a version, as though 157 were "stronger" than something numbered 100. It isn't any of those. The number is just a label.
BPC-157 is a synthetic peptide made of 15 amino acids, derived from a protein found in human gastric juice. Nearly all of its research comes from lab and animal studies. Human research is very limited, with only a handful of small, early studies published 3.
Why do some names point to a bigger "parent" molecule?
The "TB" in TB-500 refers to thymosin beta-4, a natural peptide made of 43 amino acids that is found throughout the body. TB-500 is usually described as a short synthetic piece of it, about seven amino acids long 4.
A piece of the string is not the same string. Think back to our beads-on-a-string picture 5. A seven-bead piece of a 43-bead string has a different shape, and a different shape can mean different effects. So when you see research on thymosin beta-4, it doesn't automatically apply to TB-500.
TB-500 is an informal label rather than an official drug name. Its published research is limited to lab and animal settings, and it is on the World Anti-Doping Agency's list of prohibited substances for athletes 4.
What does "-relin" mean?
Now we get to official drug names. In the United States, generic drug names are assigned by the USAN Council, which uses shared word parts called stems so that related drugs sound related 1,2.
The stem "-relin" is used for peptides that stimulate the release of a hormone. Narrower versions point to a specific hormone. For example, "-morelin" marks peptides that stimulate the release of growth hormone 1.
| Name | Stem | Status |
|---|---|---|
| sermorelin | -morelin → release growth hormone | Compared later in this series |
| tesamorelin | -morelin → release growth hormone | FDA-approved |
| ipamorelin | -morelin → release growth hormone | Not approved |
Sharing an ending means drugs share a broad job. It doesn't mean they are equally studied or equally regulated. Tesamorelin is an FDA-approved medicine for a specific use. Ipamorelin is not approved. We compare sermorelin and tesamorelin in detail later in this series.
What does "-tide" mean?
The stem "-tide" is used for peptide drugs in general. Some versions are more specific. Names ending in "-glutide", such as semaglutide, point to drugs related to GLP-1, the gut hormone we described in our last guide 1.
| Name | Ending | What it tells you |
|---|---|---|
| semaglutide | -glutide | Related to GLP-1 |
| tirzepatide | -tide | Peptide drug |
| teriparatide | -tide | Peptide drug |
| bremelanotide | -tide | Peptide drug |
You may recognize several of these names from that guide's list of FDA-approved peptide medicines. Their endings tell you what they are made of before you look anything up.
Which names don't follow the pattern?
Two kinds of names don't fit these rules:
- Older natural names. Insulin and oxytocin were named long before the modern system existed, so they don't end in "-tide", even though both are peptides.
- Informal lab names. BPC-157 and TB-500 don't have official generic names. They're nicknames and lab codes used in research papers and online 3,4.
That second point is a useful clue. Getting an official name like "-relin" or "-tide" is a step on the path toward becoming a medicine, so a name without one usually means the compound hasn't been through formal drug development. That isn't a verdict on the compound, but it's a reason to ask more questions.
How do the four patterns compare?
| Pattern | Example | What it tells you | What it doesn't |
|---|---|---|---|
| Number in the name | BPC-157 | It's a lab label or catalog number | Strength, dose or quality |
| Points to a parent | TB-500 | It's related to a bigger molecule (thymosin beta-4) | That it works like the parent |
| Ends in "-relin" | Sermorelin, tesamorelin | Designed to trigger the release of a hormone | Whether it's approved or well studied |
| Ends in "-tide" | Semaglutide, teriparatide | It's a peptide drug with an official name | Whether it's right for anyone |
How should you read any peptide name?
Three habits:
- Look for the ending. "-relin" and "-tide" give you a quick clue about a molecule's family and job.
- Don't read numbers as strength. "157" and "500" are labels, not measurements.
- Notice when a name is informal. No official name usually means no formal drug development yet, so look harder at the evidence.
The takeaway
Numbers are labels, some names point to a bigger parent molecule, "-relin" usually signals "release a hormone", and "-tide" usually signals "peptide drug".
A name can tell you what kind of molecule you're looking at. It can never tell you whether it works or whether it's safe. For that, go back to question four: where did it come from, and what's the evidence?
References
- [1]United States Adopted Names approved stemsAmerican Medical Association · AMA
- [2]United States Adopted NameWikipedia
- [3]BPC-157Wikipedia
- [4]TB-500Wikipedia
- [5]PeptideNational Human Genome Research Institute · Talking Glossary of Genomic and Genetic Terms (NIH)
- [6]Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety RisksU.S. Food and Drug Administration · FDA
- [7]Benefits & Risks of Peptide Therapeutics for Physical & Mental HealthHuberman Lab (episode summary) · 2024
Frequently asked questions
What does the 157 in BPC-157 mean?
It's part of the compound's lab designation, like a catalog number. It isn't a dose, a strength or a version, and it doesn't mean BPC-157 is "stronger" than something numbered 100.
Is TB-500 the same as thymosin beta-4?
No. Thymosin beta-4 is a natural peptide of 43 amino acids. TB-500 is usually described as a short synthetic piece of it, about seven amino acids long. A different shape can mean different effects, so research on thymosin beta-4 doesn't automatically apply to TB-500.
What does "-tide" mean at the end of a drug name?
It's a naming stem used for peptide drugs. Narrower versions point to a specific family. For example, "-glutide" marks drugs related to GLP-1, such as semaglutide.
Why don't insulin and oxytocin end in "-tide"?
They were named long before the modern naming system existed. Both are peptides, but older natural names don't follow today's patterns.
Related peptides
- TB-500 / Thymosin Beta-4Healing & RecoveryRead the guide to TB-500 / Thymosin Beta-4 →SafetyInsufficient DataEvidencePreliminary
The Pepwise Research Team reads the published research on peptides and summarises what it does and does not show.