THE TERMS DECODED.

A molecule that binds a receptor and activates it. GLP-1 agonists activate the GLP-1 receptor, mimicking the natural hormone.

The building blocks of peptides and proteins. Twenty standard amino acids combine in sequences to form all peptides.

The cellular 'energy sensor.' When ATP runs low, AMPK activates and shifts metabolism toward fat burning and away from growth.

A measure of total drug exposure over time — used in pharmacokinetics to compare dosing regimens.

Sterile water containing 0.9% benzyl alcohol, used to reconstitute lyophilized peptides. Prevents bacterial growth during the 28-day use window.

The fraction of an administered dose that reaches systemic circulation. Oral bioavailability is typically near zero for peptides (exceptions: BPC-157, KPV).

A lab-issued document verifying the identity, purity, and quality of a compound. Look for third-party HPLC results ≥99% purity.

Maximum concentration of a drug in plasma after a dose.

A phospholipid on the inner mitochondrial membrane. SS-31 selectively binds and protects it.

Dipeptidyl peptidase-4. Enzyme that degrades native GLP-1 in minutes. Why peptides like semaglutide are engineered to resist it.

A compound reviewed and authorized by the U.S. Food and Drug Administration for specific medical indications. Currently approved peptides include semaglutide, tirzepatide, tesamorelin, liraglutide, PT-141, and others.

Glucose-dependent insulinotropic polypeptide. A gut hormone; target of tirzepatide (along with GLP-1).

Glucagon-like peptide-1. Gut hormone released after eating; regulates insulin, gastric emptying, and appetite. Target of semaglutide, tirzepatide, retatrutide.

Growth hormone-releasing hormone. The pituitary upstream signal. Sermorelin, tesamorelin, CJC-1295 are GHRH analogs.

Time for plasma concentration to decrease by half. Drives dosing frequency — BPC-157 (~4h) dosed BID; semaglutide (~1 week) dosed weekly.

High-performance liquid chromatography. The gold-standard method for verifying peptide purity. Look for ≥99% on a COA.

Insulin-like growth factor 1. Downstream mediator of growth hormone. Many anabolic effects of GH are IGF-1-mediated.

Freeze-dried powder form. How most research peptides ship. Must be reconstituted with bacteriostatic water before injection.

Metabolic-associated / non-alcoholic steatohepatitis — fatty liver inflammation. Target of survodutide, semaglutide, retatrutide.

How a compound produces its effect at the molecular level — receptor binding, enzyme inhibition, pathway modulation.

The mass of a molecule, measured in daltons (Da). Useful for mass-spec verification of identity.

Nicotinamide adenine dinucleotide. Central metabolic cofactor; declines with age. Target of longevity compounds.

Nicotinamide N-methyltransferase. Enzyme that consumes NAD+ precursors; inhibitors like 5-Amino-1MQ increase NAD+ bioavailability.

A short chain of amino acids (typically 2–50 residues) joined by peptide bonds. Longer chains = proteins.

The study of what the body does to a drug — absorption, distribution, metabolism, excretion.

Dissolving a lyophilized peptide powder in bacteriostatic water before injection. See our reconstitution calculator.

The plasma concentration reached when input (dosing) equals output (clearance). Typically achieved after ~4–5 half-lives.

Injection into the fatty tissue beneath the skin. Most common route for peptide research dosing.

Gradual dose escalation to improve tolerability. Standard for GLP-1s — start 0.25mg, increase monthly.

An insulin syringe calibrated in units, where 100 units = 1 mL. Default for peptide research dosing.

Vascular endothelial growth factor. Drives new blood vessel formation. BPC-157 and TB-500 both influence VEGF signaling.

World Anti-Doping Agency. Maintains the prohibited-substances list for competitive sport. Most research peptides are WADA-banned.