Core terms
- Amino acid — the building block of peptides and proteins; twenty are used by the human body
- Analogue — a modified version of a natural peptide, usually altered to resist degradation
- Bacteriostatic water — sterile water with 0.9% benzyl alcohol, used for multi-dose reconstitution
- Bioavailability — the fraction of a dose that reaches circulation intact
- Half-life — the time for plasma concentration to fall by half
- Lyophilised — freeze-dried into a stable powder
- Reconstitution — dissolving lyophilised powder into liquid for dosing
- Secretagogue — a compound that causes a gland to release its hormone
- Subcutaneous (SubQ) — injected into the fat layer beneath the skin
- Titration — gradually increasing a dose to build tolerance
Signalling and receptors
- Agonist — binds a receptor and activates it
- Antagonist — binds a receptor and blocks it
- Angiogenesis — the formation of new blood vessels
- BDNF — brain-derived neurotrophic factor, central to learning and neural repair
- GHRH / GHRP — the two receptor pathways that trigger growth-hormone release
- GLP-1 / GIP — incretin hormones governing insulin, appetite and gastric emptying
- IGF-1 — insulin-like growth factor 1, the main downstream marker of GH activity
- Downregulation — a receptor becoming less responsive after sustained stimulation