Glossary
Forty terms you meet in this field, in plain language. From agonist to purity.
A to G
| Term | Meaning |
|---|---|
| Agonist | Substance that fits a receptor and switches it on. |
| Albumin | Protein abundant in blood. Peptides with a fatty acid tail clamp onto it and so last longer. |
| Amino acid | The building block of peptides and proteins. Twenty occur as standard. |
| Analogue | A copy of a natural substance, modified to be more stable or more selective. |
| Antagonist | Substance that fits a receptor but switches nothing on and occupies the spot. |
| Bacteriostatic water | Water with 0.9% benzyl alcohol. Slows bacterial growth, so a vial can be punctured more than once. |
| Blend | Mixture of two or more peptides in one vial. |
| CoA | Certificate of analysis for a batch. |
| DAC | Drug affinity complex. An addition that binds chemically to albumin, making a peptide last days instead of minutes. |
| Downregulation | A cell removes receptors from its surface after prolonged stimulation. |
| DPP-4 | Enzyme that cuts GLP-1 within two minutes. Every GLP-1 analogue is protected against it. |
| GHRH | The hormone from the hypothalamus telling the pituitary to make growth hormone. |
| Ghrelin | Hormone of an empty stomach. Also releases growth hormone through a second route. |
| GLP-1 | Gut hormone released after a meal, involved in satiety and insulin. |
H to P
| Term | Meaning |
|---|---|
| Half-life | The time in which half of a substance has left the bloodstream. |
| HPLC | Separation technique used to measure purity. |
| Hydrolysis | Breakdown by water. The main reason powder keeps longer than a solution. |
| Pituitary | Gland at the base of the brain that releases growth hormone. |
| IGF-1 | The substance the liver makes in response to growth hormone, and which does most of the work in tissues. |
| Incretin | Collective name for gut hormones that warn the pancreas as soon as food passes. |
| Lyophilisation | Freeze drying. Freezing and letting the ice evaporate under vacuum, leaving a dry cake. |
| Lot number | The production batch number. Must match on vial and certificate. |
| MS | Mass spectrometry. Weighs the molecule and so confirms it is the right substance. |
| Peptide bond | The link between two amino acids. |
| PEG | Synthetic chain draped around a peptide like a coat to make it last longer. |
R to Z
| Term | Meaning |
|---|---|
| Receptor | Protein in the cell wall that responds to a particular shape and passes on a signal. |
| Reconstitute | Dissolve a freeze dried powder again. |
| Research use only | Legal status: not assessed for use in humans or animals. |
| Selectivity | How sharply a substance tells related receptors apart. |
| Sequence | The order of the amino acids. Sets the shape and so the action. |
| Somatostatin | The brake on the growth hormone axis. |
| SPPS | Solid phase peptide synthesis. The standard method for building a peptide. |
| Stack | Informal term for a combination of several substances. |
| Triple agonist | Substance that switches on three different receptors at once. |
| Fatty acid tail | A fatty acid on a peptide that clamps onto albumin and extends its duration. |
| Vial | Glass bottle with a rubber cap. |
| Purity | The share of your substance against everything the HPLC detector saw. |
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Visit the shopWhat this site is and is not
This site explains what the scientific literature says about peptides. It is not medical advice and not a set of instructions. The substances discussed here are research compounds: they are not approved for use in humans or animals. If you have a health question, see a doctor.
This site explains what the scientific literature says about peptides. It is not medical advice and not a set of instructions. The substances discussed here are research compounds: they are not approved for use in humans or animals. If you have a health question, see a doctor.
Read next
Reading a certificate of analysis
What belongs on a CoA, what a purity figure does and does not mean, and how to tell whether a certificate belongs to your vial.
How does a receptor work?
Agonist, antagonist, selectivity and downregulation. The terms that appear in every peptide article, explained in plain language.