Research Disclaimer: All compounds described are sold exclusively for in-vitro and laboratory research use. Not for unsupervised use. This content does not constitute medical advice.
Research compound science has a specialized vocabulary drawn from pharmacology, biochemistry, and analytical chemistry. This glossary covers the key terms that appear throughout research compound literature, COA interpretation, and protocol design — organized by category for reference.
Pharmacokinetic Terms#
Half-life (t½): The time required for plasma concentration of a compound to decrease by 50%. After 1 half-life: 50% remains; after 4 half-lives: ~6% remains; after 5: ~3%. Used to determine dosing frequency and time to steady state.
Steady state: The plasma concentration achieved after multiple doses when the rate of drug input equals rate of elimination. Takes ~4–5 half-lives to reach. Below steady state is "ramp-up" phase; above is "decline" phase.
Cmax: Maximum plasma concentration after a single dose or after a dose in the steady-state phase.
Tmax: Time to reach maximum concentration (Cmax) after administration.
AUC (Area Under the Curve): Total drug exposure over time, measured from the plasma concentration-time curve (ng/mL × hours). Represents total systemic exposure regardless of peak shape.
Bioavailability (F): The fraction of administered dose that reaches systemic circulation unchanged. IV = 100% by definition. Oral = depends on absorption and first-pass metabolism. SC/IM for peptides = near 100% for most.
Volume of Distribution (Vd): Apparent volume in which a drug would need to be dissolved to produce the observed plasma concentration. High Vd = extensive tissue distribution. Low Vd = mostly plasma-confined.
Clearance (CL): Rate at which drug is eliminated from plasma (mL/min or L/h). Combines renal, hepatic, and other elimination routes.
First-pass metabolism: Metabolic inactivation of orally administered compounds in the liver before reaching systemic circulation.
Receptor Pharmacology Terms#
Agonist: A compound that binds a receptor and activates it, producing a biological response. Full agonist = maximum response. Partial agonist = sub-maximal response even at receptor saturation.
Antagonist: A compound that binds a receptor and blocks agonist activity without activating the receptor itself. Competitive antagonist competes with the agonist for the same binding site.
Inverse agonist: A compound that binds and reduces the receptor's constitutive (baseline) activity below normal.
EC50: Half-maximal effective concentration. The concentration at which 50% of the maximum response is achieved. Lower EC50 = higher potency.
Kd: Equilibrium dissociation constant for receptor-ligand binding. Lower Kd = higher binding affinity.
Ki: Inhibition constant — used for competitive inhibitors. Lower Ki = stronger inhibition.
Receptor selectivity: The degree to which a compound preferentially acts on one receptor subtype over others.
Desensitization / downregulation: Reduced receptor responsiveness or reduced receptor expression following prolonged agonist exposure.
Off-target effects: Pharmacological activity at receptors or targets other than the primary target. May cause unintended effects; important for protocol design.
Analytical Chemistry Terms#
HPLC (High-Performance Liquid Chromatography): Analytical technique that separates compounds based on differential partitioning between a liquid mobile phase and a solid stationary phase. Used to measure purity.
Purity (area%): In HPLC, the percentage of total UV-absorbing signal attributable to the target compound. 99% purity = 99% of detected signal is the target.
Retention time: The time between sample injection and compound detection in HPLC. Characteristic for each compound under standardized conditions.
Mass spectrometry (MS): Analytical technique that measures molecular mass (m/z = mass-to-charge ratio). Used to confirm compound identity.
ESI-MS (Electrospray Ionization-MS): Gentle ionization technique that converts large polar molecules (peptides, proteins) into multiply charged ions for MS analysis.
[M+H]+ / [M+2H]2+: Notation for ionized forms: [M+H]+ = singly protonated molecule (m/z = MW + 1); [M+2H]2+ = doubly protonated (m/z = (MW + 2) / 2).
COA (Certificate of Analysis): Laboratory document summarizing all analytical tests performed on a compound batch.
Janoshik: Independent third-party analytical laboratory (Prague, CZ) that provides verifiable COA testing for research compounds.
LAL test (Limulus Amebocyte Lysate): Test for bacterial endotoxins. Result in EU/mg (Endotoxin Units per milligram).
Semaglutide, €43 · 99.0% purityBiological / Molecular Terms#
VEGF (Vascular Endothelial Growth Factor): Growth factor that stimulates angiogenesis (new blood vessel formation). Upregulated by BPC-157 and hypoxia.
IGF-1 (Insulin-Like Growth Factor-1): Downstream mediator of GH effects; activates PI3K/Akt/mTOR → protein synthesis.
mTOR (mechanistic Target of Rapamycin): Central kinase in nutrient sensing and protein synthesis. mTORC1 activated by IGF-1, amino acids, insulin → promotes ribosome biogenesis and translation.
GH (Growth Hormone): Pituitary hormone stimulating growth, metabolism, IGF-1 production. Released in pulses; stimulated by GHRH and ghrelin.
HPTA (Hypothalamic-Pituitary-Testicular Axis): Hormonal feedback system: GnRH → LH/FSH → testosterone → negative feedback.
GnRH (Gonadotropin-Releasing Hormone): Hypothalamic decapeptide that stimulates LH and FSH release from pituitary.
LH (Luteinizing Hormone), FSH (Follicle-Stimulating Hormone): Pituitary gonadotropins. LH → Leydig cells → testosterone; FSH → Sertoli cells → spermatogenesis.
AR (Androgen Receptor): Nuclear transcription factor activated by testosterone and DHT. Mediates anabolic and androgenic gene expression.
Aromatase (CYP19A1): Enzyme converting testosterone/androstenedione to estradiol/estrone. Target of aromatase inhibitors.
DPP-4 (Dipeptidyl Peptidase-4): Serine protease that cleaves the N-terminal dipeptide of GLP-1 → inactivation. GLP-1 analogs (semaglutide) designed to resist DPP-4 cleavage.
Formulation Terms#
Lyophilization: Freeze-drying process that removes water from peptide solutions to produce stable powder for long-term storage.
BAC water (Bacteriostatic Water): Sterile water with 0.9% benzyl alcohol. Standard reconstitution solvent for research peptides; extends reconstituted peptide shelf life to 28 days at 2–8°C.
Sesame oil / MCT oil: Common vehicles for injectable anabolic compounds. Provides slow-release depot at injection site.
Co-solvent (BA/BB): Benzyl alcohol (BA, 2%) and benzyl benzoate (BB, 20%) are co-solvents used in oil-based injectables to improve compound solubility in oil vehicle.
Research Use Only. JuicedPharma does not provide medical advice.
Published by JuicedPharma Research Team · October 2026 · Category: Research Protocols & Science
