This glossary provides definitions for terms commonly encountered when reading about dosage in peptide research literature. Understanding these concepts helps in critically evaluating research publications.
- Bioavailability
- The proportion of an administered compound that reaches systemic circulation. Varies by administration route and individual factors.
- Dose-Response Curve
- A graphical representation of the relationship between dose amount and measured effect. Used to characterize how effects change with different amounts.
- ED50 (Effective Dose 50)
- The dose at which 50% of subjects show a particular response. A measure used in research to compare compound potency.
- Half-Life
- The time required for the concentration of a compound in the body to decrease by half. Affects dosing frequency in research protocols.
- International Unit (IU)
- A unit of measurement based on biological activity rather than mass. Specific to each compound and not universally convertible.
- LD50 (Lethal Dose 50)
- The dose at which 50% of test subjects die. Used in toxicology research to characterize safety margins.
- Loading Dose
- An initial higher amount sometimes used in research protocols to achieve desired concentrations more quickly.
- Maintenance Dose
- The amount used after initial administration to maintain steady-state concentrations in research protocols.
- Microgram (mcg)
- One millionth of a gram (0.000001 g). Common unit for peptide measurements. Also written as μg.
- Milligram (mg)
- One thousandth of a gram (0.001 g). Larger mass unit used for some compounds or bulk quantities.
- Pharmacokinetics
- The study of how compounds are absorbed, distributed, metabolized, and excreted by the body. Affects dosing considerations.
- Pharmacodynamics
- The study of how compounds affect the body. Describes the relationship between concentration and effect.
- Saturation Point
- The amount beyond which additional compound produces no additional effect. Receptors become fully occupied.
- Steady State
- The point at which the rate of compound entering the body equals the rate of elimination. Relevant for repeated dosing protocols.
- Subcutaneous (SC or SubQ)
- Administration under the skin. A common route for peptide research due to absorption characteristics.
- Therapeutic Index
- The ratio between the dose that produces toxicity and the dose that produces the desired effect. Higher values indicate wider safety margins.
- Trough Level
- The lowest concentration of a compound in the body, typically measured just before the next scheduled dose in research protocols.
- Volume of Distribution
- A theoretical volume that would be necessary to contain the total amount of a compound at the same concentration as in blood plasma.