Reference

Glossary

Every term used in our research summaries, defined in plain English. Where a definition carries a common misreading, we say what the term does not mean as well as what it does.

Analytical

Certificate of analysis(COA): A laboratory document reporting the results of tests run on a specific batch of material — typically identity, purity and, where relevant, water content. A certificate is only meaningful when its batch number ties it to the material it describes and when the analytical methods used are stated.
High-performance liquid chromatography(HPLC): A separation technique used to assess purity. The sample is carried through a column and its components are detected as they emerge. The reported figure is the main peak as a proportion of total detected peak area — a ratio of what the detector saw, not a measure of how much of a container is peptide.
Mass spectrometry(MS): A technique that measures molecular mass, used to confirm identity. For a peptide, the observed mass is compared with the mass calculated from the intended amino-acid sequence.
Karl Fischer titration: A method for measuring water content. Freeze-dried peptide holds residual water, which contributes mass that is not peptide.
Counter-ion: An ion paired with the peptide after purification, commonly trifluoroacetate. Like residual water, it adds mass without adding peptide, which is why net peptide content is a more informative figure than a bare purity percentage.
Lyophilisation: Freeze-drying. Removing water under vacuum leaves a dry cake that is considerably more stable than the same material in solution.

Pharmacology

Agonist: A molecule that binds a receptor and activates it, producing a response. A dual or triple agonist is described in the literature as activating two or three different receptor types.
Antagonist: A molecule that binds a receptor without activating it, blocking the effect of whatever would otherwise bind there.
Peptide: A chain of amino acids linked by peptide bonds. Chains are conventionally called peptides up to roughly fifty residues and proteins above that.
Pharmacokinetics(PK): What an organism does to a molecule over time — absorption, distribution, metabolism and elimination. Distinct from pharmacodynamics, which concerns what the molecule does to the organism.
Half-life: The time taken for the concentration of a substance in circulation to fall by half. Reported values are population averages from specific study conditions.

Study design

In vitro / in vivo: In vitro means in cells or isolated systems outside a living organism. In vivo means in a living organism. Most research-peptide literature is in vitro or in animal models.
Preclinical: Research conducted before human trials — cell models and animal studies. Preclinical findings can establish plausibility and mechanism; they do not establish efficacy or safety in people.
Randomised controlled trial(RCT): A study in which participants are assigned by chance to an intervention or a control, reducing the influence of selection bias. Double-blind means neither participants nor assessors know the assignment.
Phase 1, 2 and 3: Successive stages of clinical study. Phase 1 examines safety and handling in small groups, phase 2 explores dose-response and preliminary effect, phase 3 tests effect against a comparator in larger populations. Authorisation decisions rest chiefly on phase 3.
Endpoint: The outcome a study is designed to measure. A surrogate endpoint is a laboratory or imaging measure standing in for a clinical outcome such as illness or survival.
Placebo-controlled: A design in which a comparison group receives an inactive preparation, allowing investigators to separate the effect of the intervention from expectation and from the natural course of a condition.
Peer review: Assessment of a manuscript by independent specialists before a journal publishes it. Peer review filters, but does not guarantee, quality — which is why study design and sample size still matter to a reader.

Regulatory

Marketing authorisation: A regulator's licence permitting a medicine to be marketed for a stated indication. Without one, a compound is unlicensed: no approved indication, no patient information leaflet and no permitted health claims.
MHRA: The Medicines and Healthcare products Regulatory Agency, the United Kingdom body responsible for authorising and regulating medicines and medical devices.
Unlicensed reference material: A chemical supplied for laboratory work rather than for administration to people or animals. It is not a medicine and carries no approved use.
WADA Prohibited List: The list published annually by the World Anti-Doping Agency naming substances and methods banned in sport. Inclusion is a regulatory classification, not a scientific finding about a compound.