Peptide Glossary
Definitions for 29+ terms used in peptide research, dosing, and reconstitution.
Amino Acid
The basic building blocks of peptides and proteins. There are 20 standard amino acids, each with a unique side chain that determines its chemical properties.
Bacteriostatic Water (BAC Water)
Sterile water containing 0.9% benzyl alcohol as a preservative. The standard diluent for reconstituting research peptides. The benzyl alcohol prevents bacterial growth, allowing the vial to be used multiple times.
Blend
A single vial containing two or more peptides pre-mixed by the manufacturer at fixed ratios. Contrasted with a stack, which uses multiple separate vials.
Concentration
The amount of peptide dissolved per unit volume of solution, typically expressed in mg/mL or mcg/mL. Determined by dividing the total peptide amount by the volume of BAC water added during reconstitution.
DAC (Drug Affinity Complex)
A chemical modification (maleimidoproprionic acid) added to CJC-1295 that allows it to bind to albumin in the bloodstream, extending its half-life from ~30 minutes to 6–8 days.
Diluent
The liquid used to dissolve (reconstitute) a lyophilized peptide. For research peptides, bacteriostatic water is the standard diluent.
Dose
The amount of a substance administered at one time, typically expressed in mg or mcg for peptides.
GHK-Cu
Glycyl-L-histidyl-L-lysine copper complex. A naturally occurring copper-binding tripeptide involved in wound healing, collagen synthesis, and anti-inflammatory activity.
GHRH (Growth Hormone-Releasing Hormone)
A hypothalamic hormone that stimulates the pituitary gland to release growth hormone. CJC-1295 is a synthetic GHRH analogue.
GHRP (Growth Hormone-Releasing Peptide)
A class of synthetic peptides that stimulate GH release via ghrelin receptor activation. Examples include GHRP-2, GHRP-6, and Ipamorelin.
GLP-1 (Glucagon-Like Peptide-1)
An incretin hormone secreted by intestinal L-cells that stimulates insulin secretion, reduces glucagon, slows gastric emptying, and reduces appetite. Semaglutide and tirzepatide are GLP-1 receptor agonists.
Half-Life
The time it takes for the concentration of a substance in the body to be reduced by half. Relevant for determining dosing frequency.
IU (International Unit)
A unit of measurement for biological activity, used for some peptides (e.g., HGH, insulin). Not interchangeable with mg or mcg without a conversion factor specific to each substance.
Lyophilization
Freeze-drying. The process of removing water from a frozen solution under vacuum, converting it directly from ice to vapor (sublimation). Used to preserve peptides for storage and shipping.
mcg (Microgram)
One-millionth of a gram (0.000001 g) or one-thousandth of a milligram (0.001 mg). Many research peptides are dosed in micrograms.
mg (Milligram)
One-thousandth of a gram (0.001 g). Equal to 1,000 micrograms (mcg).
mL (Milliliter)
One-thousandth of a liter. The unit used to measure injection volumes. On a U-100 syringe, 1 mL = 100 units.
Peptide
A short chain of amino acids (typically fewer than 50) linked by peptide bonds. Peptides occur naturally in the body as hormones, neurotransmitters, and signaling molecules. Research peptides are synthetic versions of naturally occurring peptides or novel sequences.
Reconstitution
The process of dissolving a lyophilized (freeze-dried) peptide powder in a liquid diluent (typically BAC water) to create an injectable solution of known concentration.
Secretagogue
A substance that stimulates the secretion of another substance. Growth hormone secretagogues (like Ipamorelin) stimulate the pituitary to release GH.
Stack
A protocol using multiple separate peptide vials administered together according to a combined schedule. Contrasted with a blend, which is a single vial containing multiple peptides.
Sterile Water for Injection (SWFI)
Sterile water without preservatives. Not recommended for multi-use vials because it does not prevent bacterial contamination after the first use. BAC water is preferred for research peptides.
SubQ (Subcutaneous)
Under the skin. The standard injection route for most research peptides. Subcutaneous injections are made into the fatty tissue just below the skin, typically in the abdomen, thigh, or upper arm.
Thymosin Beta-4 (TB-500)
A 43-amino-acid peptide that regulates actin polymerization, promotes cell migration, and supports tissue repair. TB-500 is a synthetic version used in research.
Titration
The process of gradually increasing a dose over time to find the minimum effective dose or to minimize side effects. Common with GLP-1 agonists like semaglutide and tirzepatide.
U-100 Syringe
An insulin syringe calibrated for U-100 insulin (100 units per mL). Each unit on the syringe equals 0.01 mL. The standard syringe for subcutaneous peptide injections.
Vial
A small glass container with a rubber stopper used to store lyophilized peptide powder or reconstituted peptide solution.
VEGFR2 (Vascular Endothelial Growth Factor Receptor 2)
A receptor tyrosine kinase that mediates angiogenesis (new blood vessel formation). BPC-157 activates VEGFR2 signaling, which is one mechanism by which it promotes tissue repair.
WADA (World Anti-Doping Agency)
The international organization that maintains the list of substances prohibited in competitive sports. Many research peptides (including TB-500, BPC-157, and GH secretagogues) are on the WADA prohibited list.