Glossary
The terms you meet on lab reports, product pages and in the research library, in one or two sentences each.
- Agonist
- A molecule that binds to a receptor and activates it, producing a response like the natural ligand.
- Aib (α-aminoisobutyric acid)
- A non-standard amino acid used in peptide design to protect against breakdown by enzymes such as DPP-4.
- Assay
- A measurement of how much of the target substance a sample contains, compared with the declared amount.
- Batch (lot) number
- The identifier that links a vial to the production run and to its certificate of analysis. Read more
- CAS number
- A unique registry number for a chemical substance. Retatrutide’s CAS number is 2381089-83-2.
- Certificate of analysis (COA)
- A laboratory report with the test results for one specific batch. Read more
- Counter-ion
- An ion, such as acetate or trifluoroacetate, that stays with a peptide after purification and adds to the powder’s weight.
- DPP-4
- Dipeptidyl peptidase-4, an enzyme that quickly breaks down native GLP-1 and GIP.
- Endotoxin
- Material from bacterial cell walls. Measured with the LAL test and reported in EU per mg.
- GIP
- Glucose-dependent insulinotropic polypeptide, an incretin hormone from K-cells in the upper small intestine. Read more
- GLP-1
- Glucagon-like peptide-1, an incretin hormone from L-cells in the lower intestine. Read more
- Glucagon receptor
- A receptor, mainly in the liver, that responds to the hormone glucagon. Read more
- GPCR
- G-protein-coupled receptor: the receptor family that includes the GIP, GLP-1 and glucagon receptors.
- HPLC
- High-performance liquid chromatography, the standard method for measuring peptide purity. Read more
- Incretin
- A gut hormone that increases insulin release after a meal. GIP and GLP-1 are the two main incretins.
- ISO/IEC 17025
- The international standard for the competence of testing and calibration laboratories.
- Karl Fischer titration
- A method for measuring the water content of a sample.
- LC-MS
- Liquid chromatography coupled to mass spectrometry, used to confirm a peptide’s identity by its mass.
- Lyophilisation
- Freeze-drying: removing water from a frozen product under vacuum, so it stays stable as a powder. Read more
- LY3437943
- Eli Lilly’s development code for retatrutide. Read more
- Net peptide content
- The share of a peptide powder’s weight that is the peptide itself, excluding water and counter-ions.
- Triple agonist
- A single molecule that activates three different receptors — for retatrutide, the GIP, GLP-1 and glucagon receptors. Read more