Selective Androgen Receptor Modulators in Pharmacokinetics and Doping Control

Selective androgen receptor modulators (SARMs) are a class of non-steroidal compounds engineered to bind selectively to the androgen receptor, evoking anabolic effects in muscle and bone while limiting undesirable androgenic activity in reproductive tissues. Their tissue-selective profile has spurred both clinical interest in conditions such as muscle wasting and osteoporosis and illicit use in athletic settings. Understanding SARM pharmacokinetics—absorption, distribution, metabolism and excretion—is essential for interpreting anti-doping test results and differentiating deliberate doping from inadvertent exposure through contaminated supplements. Metabolite profiling, detection windows and dose–metabolite ratios have emerged as critical tools in result management, enabling anti-doping authorities to estimate the timing and magnitude of intake. Advances in high-resolution mass spectrometry and micro-dose excretion studies have refined our capacity to detect minute concentrations of parent compounds and multiple phase I and phase II metabolites, extending detection periods to weeks or even months post administration. Such developments carry global significance, supporting harmonised testing strategies, informing therapeutic monitoring and reinforcing the integrity of competitive sport.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Selective Androgen Receptor Modulators in Pharmacokinetics and Doping Control publication trend

The graph below shows the total number of articles in selective androgen receptor modulators in pharmacokinetics and doping control across all publications each year (not limited to Nature Index journals).

Technical terms

Selective Androgen Receptor Modulator (SARM): A compound that binds to the androgen receptor with tissue-selective activity, promoting anabolic effects in muscle and bone while minimising actions in reproductive tissues.

Pharmacokinetics: The study of how a substance is absorbed, distributed, metabolised and excreted by the body, determining its concentration–time profile.

Phase I Metabolite: A biotransformation product generated by enzymatic oxidation, reduction or hydrolysis, often more polar than the parent compound.

Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS): An analytical technique combining chromatographic separation with mass analysis to detect and quantify compounds and their metabolites with high sensitivity.

Metabolite Ratio: The proportional relationship between parent compound and metabolite concentrations used to infer dose magnitude and time since administration.

Micro-dose Study: A controlled administration of sub-therapeutic quantities of a compound to characterise its pharmacokinetics without eliciting pharmacodynamic effects.

References

1. Variation of Sequential Ligandrol (LGD-4033) Metabolite Levels in Routine Anti-Doping Urine Samples Detected with or without Other Xenobiotics. Molecules (2023).
2. Human In Vivo Metabolism and Elimination Behavior of Micro-Dosed Selective Androgen Receptor Modulator RAD140 for Doping Control Purposes. Metabolites (2022).
3. Investigations into the elimination profiles and metabolite ratios of micro-dosed selective androgen receptor modulator LGD-4033 for doping control purposes. Analytical and Bioanalytical Chemistry (2021).