A masking agent is a

reagent In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...

used in

chemical analysis Analytical chemistry studies and uses instruments and methods to separate, identify, and quantify matter. In practice, separation, identification or quantification may constitute the entire analysis or be combined with another method. Separati ...

which reacts with

chemical species A chemical species is a chemical substance or ensemble composed of chemically identical molecular entity, molecular entities that can explore the same set of molecular energy levels on a characteristic or delineated time scale. These energy levels ...

that may interfere in the analysis. In sports a masking agent is used to hide or prevent detection of a banned substance or illegal drug like

anabolic steroids Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic androgens that are structurally related and have similar effects t ...

stimulants Stimulants (also often referred to as psychostimulants or colloquially as uppers) is an overarching term that covers many drugs including those that increase activity of the central nervous system and the body, drugs that are pleasurable and inv ...

Diuretics A diuretic () is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics in ...

are the simplest form of masking agent and work by enhancing water loss via urine excretion and thus diluting the urine, which results in lower concentrations of the banned substance as more of it is being excreted from the body making it more difficult for laboratories to detect. Masking Agents FAQ, National Strength and Conditioning Assoc.

References

* Analytical chemistry {{analytical-chemistry-stub