Glossary

One milligram is one thousand micrograms. Most peptide figures are quoted in micrograms and most vials are labelled in milligrams, which is where a thousand-fold error becomes possible.

The standard insulin syringe scale: 100 units to 1 millilitre. It measures volume, not amount of compound — the same 10 units contains different amounts depending on how you reconstituted.

Freeze-dried into a stable powder. This is how peptides are shipped and stored before water is added.

Certificate of Analysis — a laboratory document stating a batch’s identity and purity. A COA is only as trustworthy as the laboratory that issued it and the batch number it references.

A label indicating a compound is not approved for human use. It is a regulatory statement about approval status, not a claim about safety in either direction.

A short chain of amino acids — conventionally fewer than about fifty; longer chains are proteins. Many peptides act as signals between cells, which is why so many are studied as drugs and why so few have finished that journey.

A family of very short peptides — two to four amino acids — mostly of Russian origin, marketed as organ-specific regulators. Human evidence is thin across the whole family, which is why we list them in their own table rather than grade them alongside the compounds.

Research done before any human trial: cell cultures and animals. Necessary, informative and not transferable — a preclinical result is a reason to run a human study, not a substitute for one.

The biological pathway by which a compound is proposed to act. A mechanism is an explanation, not a result: it says how something could work in people, not whether it does.

A human study in which participants are assigned by chance to the compound or to a comparator. The design that best separates a real effect from expectation and coincidence. Our trial counts come from ClinicalTrials.gov.

The staged sequence of human trials. Phase I tests safety in small groups; Phase II tests effect and dose range in patients; Phase III confirms the effect at scale before approval. Most compounds on this site have never entered Phase I.

An inactive comparator given to part of a trial’s participants. The difference between the compound arm and the placebo arm is the effect; the placebo arm’s own improvement is why uncontrolled reports overstate everything.

Our five-level label for the weight of human evidence behind a compound: FDA-approved, Extensively studied, Well-researched, Emerging, Limited. It measures how much is known — never how well something works, and never whether to use it.

What an authority — the SFDA, FDA or EMA — has formally decided about a compound: approved for an indication, withdrawn, or never reviewed. Independent of the evidence grade; the two are shown separately on every compound page.

Use of an approved medicine for an indication other than the one it was approved for. Lawful for a prescribing physician in most jurisdictions; the evidence for the off-label use is a separate question from the approval.

The World Anti-Doping Agency. Its Prohibited List names substances banned in sport; many peptides sit in class S2, peptide hormones and growth factors. A listing is a sport ruling, not a medical one.

A section of US federal law under which licensed pharmacies may compound medicines for individual prescriptions. An FDA advisory committee, PCAC, reviews which bulk substances may be used; the flag on our chart marks compounds that have come before that committee.

The time for the concentration of a compound in the body to fall by half. Short half-lives are why many native peptides are impractical as medicines, and why modified versions with long ones — the weekly incretins — were engineered.

The order of amino acids in a peptide, written in one- or three-letter codes. Two products with the same name and different sequences are different compounds.

The percentage of a batch that is the stated compound, usually measured by HPLC. It says nothing about what the remainder is, about sterility, or about endotoxin — each of those is a separate test.

Fragments of bacterial cell walls that provoke fever and inflammation if injected. A field on a proper COA, tested separately from purity: a batch can be 99% pure and still contaminated.

Sterile water containing 0.9% benzyl alcohol, a preservative that inhibits bacterial growth in a multi-use vial. Plain sterile water has no preservative. The two are not interchangeable for storage.

Into the fat layer beneath the skin, as opposed to intramuscular or intravenous. Most peptide trials use the subcutaneous route; where a page states a route, it is quoting the source.