Reference
Glossary
The words that show up again and again, in plain language. If a peptide page uses a term you don’t know, it’s probably here.
- Agonist
- A molecule that switches a receptor on, mimicking the body's own signal. Most peptides here are agonists of one receptor or another.
- AMPK
- A cellular 'low-fuel' sensor that, when activated, pushes cells to take up glucose and burn fat — the same switch exercise flips, and what MOTS-c targets.
- Angiogenesis
- The growth of new blood vessels. BPC-157's proposed repair mechanism works partly by driving angiogenesis toward injured tissue.
- Bacteriostatic (BAC) water
- Sterile water with about 0.9% benzyl alcohol added as a preservative. Used to reconstitute peptides you'll draw from over days or weeks — the preservative is why it keeps.
- Certificate of Analysis (COA)
- A lab document reporting a batch's identity and purity. The community's main trust currency — but a manufacturer's COA is not the same as independent third-party testing.
- Cycle / cycling
- Running a compound for a set period, then taking a break. Common where receptors downregulate or something can accumulate — like the copper in GHK-Cu.
- Eumelanin
- The dark, photoprotective form of skin pigment. Melanotan-1 drives eumelanin by activating the MC1R receptor — the basis of the 'tan from inside' effect.
- GHRH
- Growth-hormone-releasing hormone. A GHRH analog like CJC-1295 raises how much GH the pituitary releases per pulse.
- Half-life
- How long it takes for half a dose to clear the blood. IGF-1 LR3 was re-engineered to stretch its half-life from minutes to about a day.
- IM (intramuscular)
- Injection into muscle — deeper than SubQ, used for some peptides and larger volumes.
- Intranasal
- Delivered as a nose spray. The default route for Semax and Selank — needle-free and fast, via nose-to-brain absorption.
- IU / units
- The marks on an insulin (U-100) syringe. 100 units = 1 mL, so 'draw to 10 units' means draw 0.1 mL.
- Lyophilized
- Freeze-dried into a stable powder — how most peptides ship. You reconstitute it with bacteriostatic water before use.
- Mass spectrometry (mass spec)
- A lab method that identifies a molecule by its mass. On a COA, mass-spec confirmation is stronger evidence the vial holds what the label claims.
- Peptide
- A short chain of amino acids, smaller than a protein. These act as signals — telling cells to repair, release a hormone, or change pigment.
- Receptor
- A docking site on a cell that a signal binds to. A peptide's effects — and its side effects — come from which receptors it switches on.
- Reconstitution
- Dissolving a lyophilized peptide in bacteriostatic water to make an injectable or sprayable solution. The concentration you choose sets your dose per unit.
- Satellite cells
- Muscle stem cells that build new muscle tissue when activated — part of the (animal-data) case for IGF-1 LR3.
- Secretagogue
- A molecule that triggers a pulse of growth hormone by mimicking ghrelin at its receptor. Ipamorelin is the clean example.
- Stack
- Running two or more compounds together for a combined effect — like BPC-157 + TB-500. See the Stack Matrix.
- SubQ (subcutaneous)
- Injection into the fat layer just under the skin, with a short insulin needle. The most common route for the peptides here.
- Third-party testing
- Independent lab testing, separate from the seller or manufacturer. The gold standard for trusting purity — and rarer than a manufacturer COA.
- Titration
- Starting low and stepping a dose up gradually to find what works with the fewest side effects. Standard with retatrutide and PT-141.
- VEGF
- Vascular endothelial growth factor — the body's 'build blood vessels here' signal. BPC-157 is proposed to raise it at injury sites.