Peptide Research Glossary: Terms Explained
Peptide product pages and Certificates of Analysis are dense with terminology. This glossary defines the terms you will actually encounter when ordering and handling research peptides.
Form and preparation
Lyophilised — freeze-dried. Water is removed under vacuum from a frozen solution, leaving a stable powder cake.
Reconstitution — adding a diluent to return a lyophilised peptide to solution.
Bacteriostatic water — sterile water containing 0.9% benzyl alcohol, which inhibits bacterial growth and allows multiple vial accesses.
Acetate salt — the counter-ion form most research peptides are supplied in. It affects the net peptide content per vial slightly, which is why a COA reports peptide content separately from gross mass.
Quality and verification
HPLC — high performance liquid chromatography, the standard method for measuring purity. A purity figure of 99% means 99% of the material eluted as the target peak.
MS — mass spectrometry, used to confirm identity by measuring molecular weight against the theoretical value for the sequence.
COA — Certificate of Analysis. The batch-specific document reporting HPLC purity, MS identity confirmation, appearance and batch number.
Batch or lot number — the identifier tying a specific vial to a specific COA. A COA without a matching batch number on the vial is not verification.
Compound classes
GHRH analogue — a growth hormone releasing hormone mimic, such as CJC-1295 or Sermorelin.
GHRP — growth hormone releasing peptide, acting on the ghrelin receptor. Includes Ipamorelin, GHRP-2, GHRP-6 and Hexarelin.
GLP-1 agonist — a glucagon-like peptide-1 receptor agonist studied in metabolic research.
Dual and triple agonist — compounds acting at two or three receptors, such as Tirzepatide (GIP and GLP-1) and Retatrutide (GIP, GLP-1 and glucagon).
DAC — Drug Affinity Complex, an albumin-binding modification that extends half-life, as in CJC-1295 with DAC.
Secretagogue — a compound that stimulates the secretion of another substance, used to describe the growth hormone releasing peptides.
Measurement
mg and mcg — milligrams and micrograms. 1 mg equals 1000 mcg.
IU or units — insulin syringe graduations, where 100 units equals 1 mL. Units measure volume, not peptide mass.
Half-life — the time for half of a compound to be cleared, reported from published pharmacokinetic work.
Frequently asked questions
- What does lyophilised mean?
- Freeze-dried. The peptide is frozen and the water removed under vacuum, leaving a dry powder that is far more stable than solution.
- What is a Certificate of Analysis?
- A batch-specific document reporting HPLC purity, mass spectrometry identity confirmation, appearance and the batch number. It should match the batch number printed on your vial.
- Are insulin syringe units a measure of peptide amount?
- No. Units measure volume — 100 units equals 1 mL. The peptide amount in a given number of units depends entirely on the concentration you reconstituted to.
All information on this page is provided for laboratory and educational reference only. Peptides Lab SA (PTY) Ltd supplies compounds strictly for in-vitro research use. Nothing here is medical advice, a dosing recommendation, or a claim of human safety or efficacy.