Reference

Glossary

28 terms used across this site, defined in one or two sentences, each linked to the guide that explains it in context. Definitions describe what a term means — they are not claims about any product.

28 terms

Documents and testing

Certificate of analysis (COA): A document in which a laboratory reports specified results for an identified sample. It supports only the questions its stated methods actually asked, and only for the sample it describes.; Reading a peptide COA: identity, purity and batch matching Verifying a peptide COA: report number, laboratory and chain of custody
Lot (batch): A quantity of material produced together and identified by a single code. The lot identifier is the join between a container and any document about it, which is why a missing or mismatched lot code breaks the link.; Peptide batch records: matching catalogue listing, vial label and laboratory report
Chain of custody: The documented sequence of who held a sample, and when, between it being taken and being analysed. Most certificates for research materials do not include one, which limits how firmly a report can be tied to a specific container.; Verifying a peptide COA: report number, laboratory and chain of custody
HPLC: High-performance liquid chromatography, a separation method used to estimate how much of the detected peptide-related material is the target. Reported purity is relative to what that particular method and its conditions detect. [GenScript peptide purity guidance]; Purity, peptide content and biological activity are three different measurements
Mass spectrometry (MS): A method that measures mass-to-charge ratio and is used to ask whether observed material is consistent with the expected molecule. It addresses identity, which chromatographic purity presupposes rather than proves.; Reading a peptide COA: identity, purity and batch matching
Purity: A relative, method-specific measurement of how much of the detected peptide-related material is the target compound. It is not a sterility, endotoxin, stability or safety result. [GenScript peptide purity guidance]; Purity, peptide content and biological activity are three different measurements
Peptide content: The proportion of a weighed sample's mass that is actually peptide. Water, residual salts and counter-ions add mass without being the target, so content and purity can differ substantially. [MilliporeSigma peptide amount explanation]; Purity, peptide content and biological activity are three different measurements
Biological activity: Whether a material produces a defined, measurable effect in a specified biological system. It requires a biological method and cannot be read off a chromatogram or a purity percentage.; Purity, peptide content and biological activity are three different measurements
Lyophilized: Freeze-dried. It describes a physical form only, and is not a statement about identity, purity, sterility or stability. Storage still follows the instructions supplied with the specific product. [GenScript peptide storage and handling]; Planning storage for lyophilized research peptides
Blend: A listing naming more than one component in the same container. Research on each component individually is not evidence about the combination, and this site does not state ratios that have not been documented.; Single compounds and blends: why component research is not combination evidence
Research use only: A statement of intended use, not a regulatory authorization category. Health Canada has warned that such wording does not make an unauthorized injectable product legal, assessed or exempt. [Health Canada advisory, April 2026]; Research materials and authorized medicines: checking Canadian product information
DIN: Drug Identification Number: an eight-digit code attached to a specific drug product record authorized for sale in Canada. Authorization belongs to that record, not to an ingredient name. [Health Canada Drug Product Database]; Research materials and authorized medicines: checking Canadian product information

Measurement and units

Milligram (mg): One thousandth of a gram, a unit of mass. A vial's stated milligrams describe a quantity of material, not a concentration and not a peptide content figure.; Understanding peptide concentration: milligrams, millilitres and sample volume
Microgram (µg): One thousandth of a milligram, or one millionth of a gram. Confusing micrograms with milligrams changes a quantity by a factor of a thousand, which is why unit labels are worth writing out in records.; Understanding peptide concentration: milligrams, millilitres and sample volume
Millilitre (mL): One thousandth of a litre, a unit of volume. One millilitre equals 1000 microlitres (µL), the unit small sample volumes are usually expressed in.; Understanding peptide concentration: milligrams, millilitres and sample volume
Concentration: An amount per unit volume, such as milligrams per millilitre. It is computed by dividing total material by the final solution volume, and cannot be inferred from a vial's mass alone.; Understanding peptide concentration: milligrams, millilitres and sample volume
U-100: A scale label originating in insulin product labelling, where it denotes 100 insulin units per millilitre. On a graduated device it marks 100 divisions per millilitre; it does not turn a peptide mass into an insulin unit. [US insulin human prescribing information]; Understanding peptide concentration: milligrams, millilitres and sample volume

Biology and mechanism

Receptor: A protein that a signalling molecule binds to, producing a response in the cell. Naming a receptor identifies where a molecule acts; it says nothing about clinical outcomes.; GLP-1, GIP and glucagon: understanding receptor names
Agonist: A molecule that binds a receptor and activates it. Receptor activity and clinical outcomes are separate questions, established by different kinds of study.; GLP-1, GIP and glucagon: understanding receptor names
GLP-1 receptor: The receptor for glucagon-like peptide-1. Several studied compounds act here. There is no receptor named “GLP-3” in the literature, despite the term circulating online.; GLP-1, GIP and glucagon: understanding receptor names Auditing a peptide claim you saw on social media
GIP receptor: The receptor for glucose-dependent insulinotropic polypeptide, a second incretin receptor distinct from GLP-1. Some compounds are described as acting at both.; GLP-1, GIP and glucagon: understanding receptor names
Glucagon receptor: The receptor for glucagon, a hormone with effects distinct from the incretin receptors. Compounds acting at GLP-1, GIP and glucagon receptors are described as triple-receptor agonists. [Jastreboff et al., 2023]; Retatrutide: three receptor targets and one 2023 phase 2 trial

Study design

In vitro: In an isolated system such as cultured cells, outside a living organism. Useful for mechanism, silent about what happens in a whole animal or a person.; Cell studies, animal models and human trials: how to read peptide evidence
In vivo: In a living organism. The species, age, sex and conditions are part of the finding and do not transfer automatically to people.; Cell studies, animal models and human trials: how to read peptide evidence
Randomized: Participants are assigned to groups by chance, so that groups are comparable and the comparison is not shaped by who chose what. Randomization is what makes a comparator meaningful.; Reading a peptide study: population, comparator, endpoint and follow-up
Comparator: What the treatment group is compared against — placebo, another treatment, or usual care. Without knowing the comparator, a reported difference has no reference point.; Reading a peptide study: population, comparator, endpoint and follow-up
Endpoint: The specific outcome a study measured, defined in advance. A change in a marker and a change in something a person experiences are different endpoints and should not be swapped.; Reading a peptide study: population, comparator, endpoint and follow-up
Adverse event: Any unfavourable occurrence recorded during a study, whether or not it was caused by the treatment. Adverse event reporting is part of a trial's results, not an optional footnote.; Reading a peptide study: population, comparator, endpoint and follow-up

New to the subject? The learning hub arranges the guides into four reading paths.