Glossary

Jargon, translated

Complicated language is how bad claims hide. Here is the vocabulary you need, written the way you'd explain it to a friend.

35 terms

Agonist: A molecule that switches a receptor on, mimicking the body's own signal.; Most GLP-1 medicines are agonists — they imitate a natural hormone rather than block it.
AMPK: A cellular energy sensor that switches on when fuel runs low.; Central to exercise and fasting biology, and to claims made for mitochondrial peptides.
Angiogenesis: Growing new blood vessels.; Essential for healing, and also exploited by tumours — which is why it appears in both benefit and risk arguments.
Antagonist: A molecule that blocks a receptor so the natural signal can't get through.; Blocking and activating the same receptor can both be therapeutic, depending on the disease.
Bioavailability: How much of a dose actually reaches your bloodstream in an active form.; Most peptides are destroyed by digestion, which is why so many are injected.
Confidence: How settled our evidence rating is — how likely it is to change as new studies appear.; High confidence means the evidence picture looks stable. It does not mean confidence that a compound works.
Confidence interval: The range of values the true effect plausibly sits within.; A wide interval crossing zero means the headline number could be nothing at all.
Conflict of interest: A financial or professional stake in the result of a study.; It doesn't automatically invalidate findings, but it changes how much benefit of the doubt is fair.
Development status: What happened to the pharmaceutical programme behind a compound: still in trials, approved, stalled, discontinued or abandoned.; It describes a programme's fate, not a molecule's safety. And continued availability online is not evidence of safety, quality or effect.
Discontinued: Development was stopped. The reason may be commercial, a trial that missed its endpoints, or a safety finding.; Discontinued is not a verdict of dangerous. Where the reason is documented, we say which of the three it was.
Efficacy: Whether a treatment produces the intended benefit under controlled trial conditions.; Efficacy is about averages in a studied group, not a promise about any individual — and it is separate from safety.
Endpoint: The specific thing a trial measures to decide whether the treatment worked.; A trial can only answer the question it measured. If the endpoint wasn't muscle or symptoms, the trial says nothing about them.
Evidence level (L0–L5): Our shorthand for the strongest type of study behind a compound, from anecdote (L0) up to large repeated human trials (L5).; It grades the quality of evidence, not how safe, strong or advisable a compound is. It is not a star rating.
Evidence-strength score: A 0–100 summary of how much good human research exists on a question — efficacy or safety — for a compound.; It is not a percentage chance of working, a safety score, or a quality rating. A low score usually means untested, not proven bad.
Half-life: How long it takes for half of a drug to clear from your system.; It drives dosing frequency. A days-long half-life means mistakes stay with you for days.
IGF-1: Insulin-like growth factor 1, the main downstream messenger of growth hormone.; It drives tissue growth, and higher levels are linked in epidemiology to some cancer risks — the core concern with GH-axis peptides.
Incretin: A gut hormone released after eating that helps manage blood sugar and appetite.; GLP-1 and GIP are incretins; the whole modern metabolic drug class is built on them.
Indication: The specific condition and patient group a medicine is officially approved to treat.; Most peptide marketing describes uses far outside any approved indication, where the trial evidence simply doesn't exist.
Investigational: Still being tested in clinical trials, and not approved for sale as a medicine.; Investigational does not mean nearly approved, and it does not mean proven. Many investigational compounds never make it.
Mechanistic: An explanation of how something could work, based on biology rather than on measured outcomes.; A plausible mechanism is not a result. It tells you what to test next, and it can point at possible risks that were never confirmed or ruled out.
Mechanistic evidence: Evidence about how something could work, from cells, receptors or models.; Necessary for developing drugs, insufficient for recommending them. Level 1, not Level 5.
mTOR: A cellular growth switch that turns on when nutrients are plentiful.; Growth and longevity often pull in opposite directions here. More growth is not always better.
Pharmacokinetics: What your body does to a drug: absorption, distribution, metabolism, excretion.; Without human pharmacokinetic data, nobody honestly knows what a dose is doing.
Phase 1 / 2 / 3: Phase 1 checks safety in small groups, Phase 2 looks for signals of effect, Phase 3 tests it properly at scale.; Most compounds sold online never completed Phase 1. That is not a technicality.
Placebo: An inactive treatment used for comparison.; Pain and recovery respond strongly to expectation, which is why uncontrolled injury reports mislead.
Preclinical: Research done before humans are studied — cells in a dish, or animals such as rats and mice.; Promising preclinical results are a reason to run human trials, not evidence that something works in people.
RCT: Randomised controlled trial — participants are assigned by chance to treatment or control.; Randomisation is what separates 'this works' from 'these people got better'.
Receptor: A protein lock on or in a cell that a specific molecular key fits.; Which receptors a peptide hits largely determines what it does — and what it does by accident.
Receptor agonist: A molecule that switches a specific receptor on, standing in for the body's own signal.; Knowing which receptors a compound activates explains its intended effect and its side effects — but not how well it performs in trials.
Regulatory approval: A regulator such as the FDA, MHRA or EMA has judged that a medicine's benefits outweigh its risks for one specific use.; Approval is use-specific, not a stamp of general safety or superiority. Approved for one condition says nothing about other uses.
Replication: Independent researchers repeating a study and getting the same answer.; One dramatic result is a hypothesis. A replicated result is knowledge.
Route of administration: How a substance is taken: injected, swallowed, sprayed into the nose, applied to skin.; A route being sold or described is not proof it delivers a working dose, or that it is safe. Many oral and nasal peptide claims have no human data.
Safety signal: A pattern in data that raises a possible safety concern and needs further investigation.; A signal is a question, not a confirmed harm. Signals are sometimes confirmed, and often not.
Surrogate endpoint: A measurable stand-in for the outcome you actually care about.; Raising IGF-1 or shrinking a scan is not the same as living better or longer. Surrogates sometimes mislead.
Telomerase: An enzyme that rebuilds the protective caps on the ends of chromosomes.; A longevity target, but also reactivated in most cancers. Enthusiasm needs a caveat.