What Research Peptides Are

Published August 21, 2026 · Artemis Labs

Research Buyer FAQ › What Research Peptides Are

A peptide is a short chain of amino acids — the same building blocks proteins are made from, far fewer of them. This page covers the class, not single compounds. It answers what these materials are, why they ship as a dry powder, what the milligram figure on a vial means, and why most published work is done in animals.

How this page was built. These are class-level definitions. Questions about a specific compound belong on that compound’s product page, where the citations for it live. Everything described here is supplied for laboratory research use only.

What are research peptides?

Research peptides are short amino-acid chains made by chemical synthesis and sold for laboratory work, not as approved drugs. Most are copies of sequences that occur in living systems, or close variants of them. They are supplied as a dry powder in a sealed vial. Our long-form introduction to the category is the complete guide to research peptides.

What is the difference between peptide therapeutics and research peptides?

Regulatory class, not chemistry. A peptide therapeutic is an approved drug that happens to be a peptide: manufactured under GMP, sterile-filled, sold with an approved indication and prescribing information, and dispensed through pharmacies. A research peptide is a chemical supplied for laboratory work: characterised by a Certificate of Analysis, not sterile-filled, carrying no approval and no indication. The same amino-acid sequence can exist on both sides of that line — as the active ingredient in an approved product and as research-use-only material — and the two remain different articles made, tested and sold under different rules. The quality-system half of the distinction is covered in the difference between RUO and GMP; the regulatory record itself is set out in research-use-only status and FDA regulation.

What is the difference between a peptide and a protein?

Length, mostly. Both are chains of amino acids joined by the same kind of bond. Chains are usually called peptides up to roughly fifty residues and proteins above that, and the boundary is a convention rather than a law of chemistry. Longer chains fold into fixed three-dimensional shapes, which is where much of the difference in behaviour comes from. The full definition is in our glossary entry for peptide versus protein.

Are all “research peptides” actually peptides?

No. “Research peptides” is a market label, and catalogs across this market — ours included — shelve compounds under it that are not peptides at all. hCG is a glycoprotein hormone: a large, protein-sized molecule with sugar chains attached, far beyond peptide length. NAD+ is a coenzyme, not an amino-acid chain. 5-Amino-1MQ and SLU-PP-332 are synthetic small molecules. Glutathione sits at the other edge of the question: it genuinely is a peptide, a tripeptide of three residues. Oxytocin and the majority of the catalog are true peptides. Saying this plainly prevents a real confusion, because a compound’s class decides which literature applies to it and what an identity test should find. Each product page states the class its compound belongs to, and the length convention that hCG falls outside is in the peptide-versus-protein answer above.

Why are peptides sold as a dry powder?

Because dry material changes far more slowly than wet material. The reactions that break peptides down — chain cleavage, deamidation, oxidation — mostly need water to proceed. Freeze-drying takes the water out and leaves a light solid. That is why a sealed lyophilised vial has a shelf life measured in years rather than weeks.

There is a practical reason too. A powder is stable enough to survive ordinary shipping without a cold chain, which a solution is not. The storage detail sits in lyophilised peptide shelf life and storage temperature.

What does the mg on a peptide vial refer to?

It is the mass of peptide sealed inside that vial — nothing more. A vial marked 10 mg contains a nominal ten milligrams of peptide as its contents. The figure describes what is in the container, in the same way a label on a reagent bottle describes what is in the bottle.

Two things it is not. It is not a volume, which is why a 10 mg vial can look nearly empty — freeze-dried solids are extremely low in density. And it is not the same as the weight of the powder, because the powder also contains counterion salt and bound water. The measured figure and the label figure can differ for that reason, which is covered in why measured mg differs from label mg.

What is a peptide blend, and why are two compounds in one vial?

A blend is a single vial containing more than one peptide, filled together at the point of manufacture rather than sold separately. The reason is convenience and cost. Compounds studied together in the same literature are often supplied together. One vial and one Certificate of Analysis then cover the set.

Composition is what matters when comparing them. Our GLOW vial contains GHK-Cu, BPC-157 and TB-500. KLOW contains those same three plus KPV, so it is GLOW with a fourth component. The BPC-157 / TB-500 co-formulated vial holds two. Each product page lists the components, the amount of each in the sealed vial, and the CAS number for each. One honest limit applies to all of them. The blends have not been studied as blends in clinical trials. The literature is on the individual compounds.

What is the difference between a peptide and a SARM?

They are different kinds of molecule entirely. A peptide is a chain of amino acids. A SARM — selective androgen receptor modulator — is a small non-peptide compound built to bind the androgen receptor. Same shelf in some catalogs, unrelated chemistry.

The distinction has a documented enforcement dimension. In the Paradigm Peptides case, the court record states that products labelled as SARMs contained testosterone, a Schedule III substance. A label naming a compound class is not a test result, and that case is the clearest illustration of the gap. The case record is summarised under the Paradigm Peptides case record.

Are peptides steroids?

No — they are different kinds of molecule with nothing structural in common. A peptide is a chain of amino acids joined end to end. A steroid is a lipid built on a four-ring carbon skeleton — the sterane core — that living systems derive from cholesterol. Sermorelin, tesamorelin and retatrutide are peptides; no peptide is a steroid, and no steroid is a peptide. The question often arrives about hCG, which is neither: it is a glycoprotein hormone, covered in the answer on which “research peptides” are actually peptides. The neighbouring confusion — peptides versus SARMs — is answered directly above, and the SARM case record there is worth reading for what class labels can hide.

Are any of these compounds growth hormone?

No. Growth hormone is a 191-residue protein, and no compound in this catalog is growth hormone. The confusion comes from three distinct relationships that appear in the published literature. GHRH analogs — sermorelin, CJC-1295, tesamorelin — are variants of the much smaller signalling hormone that acts on the pituitary; they are studied for how they behave at the GHRH receptor, and they are not the growth hormone protein. Ipamorelin belongs to a second group, acting at a different target again, the ghrelin receptor. And AOD-9604 is a synthetic fragment corresponding to a short piece of the growth hormone molecule — a fragment of a protein is not the protein, the same way TB-500 is not the full thymosin beta-4. GHK-Cu and MOTS-c are unrelated to this axis entirely. The receptor families are sorted side by side in sermorelin vs CJC-1295 vs ipamorelin.

What is a GLP-1 receptor agonist, and how does it work?

An agonist is a molecule that binds a receptor and switches it on. GLP-1 — glucagon-like peptide-1 — is a hormone released from the gut, and its receptor sits on cells in the pancreas and elsewhere. A GLP-1 receptor agonist is a synthetic molecule shaped to bind that same receptor and send the same signal. Most are built to last longer in circulation than the natural hormone.

Compounds in this class differ by which receptors they bind. Tirzepatide is described in the literature as binding two — the GIP and GLP-1 receptors. Retatrutide is described as binding three, adding the glucagon receptor. The receptor-level mechanism is set out in our explainer on GLP-1 receptor agonism.

Which research compounds are GLP-1 receptor agonists — and which are not?

Two in this catalog are, and the rest are not. Tirzepatide is described in the literature as a dual agonist, binding the GIP and GLP-1 receptors; retatrutide as a triple agonist, adding the glucagon receptor. “Triple” counts receptors — there is no “GLP-3” among them, and no such receptor exists. Cagrilintide is the common mix-up: it is a long-acting analog of amylin, a different pancreatic hormone, and it is not an incretin agonist at all (Lau et al., Lancet 2021, PMID 34798060). BPC-157, sermorelin, MOTS-c, AOD-9604 and 5-amino-1MQ have no GLP-1 receptor activity described in their literatures — they belong to different mechanism classes entirely. The receptor mechanism itself is defined in the answer above, with the full walk-through in GLP-1 receptor agonism.

What does “peptide analog” mean?

An analog is a modified version of a known peptide. The basic sequence stays; something is changed. That might be a swapped amino acid, a shortened chain, or an added chemical group. The change is usually made to alter how long the molecule survives or how tightly it binds.

What do “in vitro” and “in vivo” mean?

In vitro means in glass — work done in a dish, a tube or a cell culture, outside a living organism. In vivo means in a living organism, most often a rodent in this literature. The two answer different questions, and a result in one does not carry over to the other on its own.

Why is nearly all peptide research done in animals?

Because human studies are expensive, slow, and require regulatory approval that most of these compounds have never been through. Animal work is where a mechanism gets established, and for a large share of the peptides in this market that is where the evidence stops. Saying so is not a criticism of the literature; it is a description of it.

The consequence for a reader is worth stating plainly. A rodent result is a rodent result. It tells you something real about a pathway. It tells you very little about what would happen in a person. That gap is where most of the overstatement in this category lives. When we describe a study on a product page, we name the model it was run in, because the model is part of the finding. Where published work cuts against a compound’s popularity, we put that on the page too.

This page is one section of the full Artemis Labs research-buyer FAQ.

References

  1. CBS News — “Peptides seller sentenced to prison for selling unapproved drugs” (Paradigm Peptides; pleas December 10, 2025; sentencing July 30, 2026, N.D. Indiana). cbsnews.com
  2. Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. “Stability of protein pharmaceuticals: an update.” Pharm Res. 2010;27(4):544–575. PMID 20143256 · doi:10.1007/s11095-009-0045-6
  3. Lau DCW, Erichsen L, Francisco AM, et al. Lancet. 2021;398(10317):2160–2172. PMID 34798060 · doi:10.1016/S0140-6736(21)01751-7. Cited for the characterisation of cagrilintide as a long-acting amylin analogue; title omitted here because it names a clinical indication.