Peptide Terminology Glossary — Key Terms Explained

Understanding peptide science starts with knowing the terminology. This glossary covers essential terms used in peptide research, reconstitution, dosing, and administration.

From amino acid sequences to subcutaneous injection techniques, this reference helps beginners and experienced researchers alike navigate peptide vocabulary.

Lyophilized

Freeze-dried. Removes water from peptide to improve stability for storage and shipping.

Reconstitution

Dissolving lyophilized peptide powder into bacteriostatic water to create an injectable solution.

BAC Water

Bacteriostatic water — sterile water with 0.9% benzyl alcohol. Standard diluent for research peptides.

SubQ (Subcutaneous)

Injection into the fatty tissue layer beneath the skin. Most common route for research peptides.

Half-Life

Time for peptide concentration in the body to reduce by 50%. Determines dosing frequency.

GLP-1

Glucagon-Like Peptide-1 — incretin hormone regulating blood sugar and appetite. Semaglutide is a GLP-1 analog.

GHRP

Growth Hormone Releasing Peptide — mimics ghrelin to stimulate GH release. Examples: GHRP-2, GHRP-6, ipamorelin.

RUO

Research Use Only — regulatory classification. Not approved for human therapeutic use.

Peptide Bond

The covalent bond linking amino acids in a peptide chain (–CO–NH–).

IU (International Unit)

Unit of measurement on a U-100 insulin syringe. 1 IU = 0.01 mL. Used to measure peptide injection volumes.