RESEARCH LANGUAGE
The glossary
Definitions with their scope intact: identity is not purity, research use is not authorization, and mechanism is not an outcome.
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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
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.
- 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.
- 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.
- 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.
- 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.
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.
- 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 receptor
- The receptor for glucagon-like peptide-1. Several studied compounds act here. On this site, GLP-3 is an informal customer-facing name for retatrutide, referring to its three named targets—GLP-1, GIP and glucagon—not to a receptor called GLP-3.
- 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.
- 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.
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.
- In vivo
- In a living organism. The species, age, sex and conditions are part of the finding and do not transfer automatically to people.
- 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.
- 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.
- 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.
- 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.