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Evidence-rated reference Updated August 2026
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Peptide Glossary

572 terms · 17 topics

572 terms from peptide chemistry, pharmacokinetics, trial design and the regulatory machinery around them — written for people reading spec sheets, trial abstracts and FDA letters rather than marketing pages. Each entry says what the term means, what it is worth in practice, and where it gets misused. We publish no dosing protocols and sell nothing.

Clinical Trials & Study Design

33 terms

How a study is built determines what its result can support. These are the design terms that decide whether a finding is evidence of effect or an artefact of the way the question was asked.

Dermatology & Cosmetic

33 terms

Topical peptides sit on the line between cosmetic and drug, and the claim language is regulated accordingly. This section covers skin biology, the measurement methods behind before-and-after claims, and where those methods are weakest.

Evidence & Statistics

34 terms

Reading a result correctly is a separate skill from running the study. This section covers the statistics that get quoted in headlines and the ones that decide whether the headline means anything.

Both panels apply an identical relative risk of 0.75 — a headline "25% reduction". Only the baseline risk differs, and the absolute benefit differs seventeen-fold with it. NNT = 1 ÷ ARR is where that difference becomes visible.

Bar pair showing a control event rate of 20 percent and a treated rate of 15 percent, an absolute risk reduction of 5 percentage points and a number needed to treat of 20.
20% baseline — 5 points absolute, NNT 20
Bar pair showing a control event rate of 2 percent and a treated rate of 1.5 percent, an absolute risk reduction of half a percentage point and a number needed to treat of 200.
2% baseline — 0.5 points absolute, NNT 200

Formulation & Delivery

34 terms

Route, formulation and handling decide how much of a dose reaches circulation and how stable it is on the way. This section covers the vocabulary of dosage forms and storage — it describes how these things work, and deliberately publishes no dosing instructions.

Growth Hormone Axis

34 terms

The somatotropic axis is tightly regulated by feedback and released in pulses, which is why stimulating it and replacing it are not the same intervention. Much of the marketing around this category depends on eliding that difference.

Hormonal & Reproductive

34 terms

Endocrine axes are feedback systems, so intervening at one point moves several others. These terms cover the axes, the assays used to read them, and the recovery questions that follow any suppression.

Immune & Inflammatory

34 terms

Immune vocabulary is borrowed heavily by peptide marketing, usually without the qualifiers. These entries define the mechanisms precisely enough that you can tell a described mechanism from a demonstrated effect.

Manufacturing & Analysis

34 terms

How a peptide is made and what a test can actually prove about the vial in front of you. A purity figure is a narrower claim than most readers assume, and several of the things buyers most want verified are not what the certificate reports.

Metabolic & Incretin Biology

33 terms

The biology the incretin drugs act on, and the measurements used to judge them. Understanding why glucose-dependent insulin release behaves differently from insulin itself explains most of what is distinctive about this drug class.

Neurology & Cognition

33 terms

Getting a peptide into the brain is the hard problem this whole category orbits. Terms here cover the barrier itself, the signalling that gets claimed, and why so many compounds with striking rodent cognition data have gone nowhere in humans.

Peptide Chemistry & Structure

34 terms

Almost every property a peptide has — how long it survives in plasma, whether it can be swallowed, whether the immune system notices it — traces back to its sequence and the modifications hung off it. These are the structural terms that spec sheets assume you already know.

Pharmacokinetics & Dosing Concepts

34 terms

Pharmacokinetics is where peptide engineering shows its hand. The same peptide backbone can be cleared in two minutes or last a week depending on what has been done to it, and the numbers on a spec sheet only mean something once you know which quantity they name.

Each curve solves C(t) = C₀·e^(−kt) with k = ln2 ÷ t½. The dots mark successive half-lives, which is why the same fraction disappears in every interval regardless of where you start.

Exponential decay curve for a six-hour half-life over 36 hours, with points marking 50, 25 and 12.5 percent of peak concentration.
t½ = 6 h — gone within a day
Exponential decay curve for a twenty-four-hour half-life over six days, with points marking each successive halving of concentration.
t½ = 24 h — the daily-dosing shape
Exponential decay curve for a seven-day half-life over six weeks, showing how slowly an acylated weekly peptide leaves the body.
t½ = 7 d — a weekly-injection profile

Pharmacology & Mechanism

34 terms

What a molecule does at its receptor, and the vocabulary for saying it precisely. The distinctions here are the ones marketing copy most often collapses: potency is not efficacy, affinity is not activity, and a compound that binds is not thereby a compound that works.

Regulation & Approval

34 terms

Approved, cleared, authorised, compounded and unapproved are five different things, and the difference is the whole subject of this section. Regulatory positions move, so treat the mechanisms here as durable and the current status of any given compound as something to check.

Safety & Pharmacovigilance

32 terms

Harm is characterised, coded and reported through a specific machinery, and knowing that machinery tells you what the absence of a reported signal does and does not mean. These terms cover adverse events, monitoring, and the limits of spontaneous reporting.

Sourcing, Markets & Misuse

34 terms

How peptides actually reach people, and where that supply chain fails them. These entries describe the market and its failure modes; none of them is a guide to obtaining anything, and pepteyes.com links to no supplier.

Tissue Repair & Musculoskeletal

34 terms

This is the category with the widest gap between what is claimed and what has been shown in humans. The biology of healing is well described; the evidence that any given peptide accelerates it in people is, for most compounds here, thin or absent.