# Avoid Falsely Accusing Female Athletes Who Use Levonorgestrel of Doping

## TL;DR

This study shows that using levonorgestrel, a contraceptive, can lead to detection of a metabolite linked to a banned substance, highlighting the need for proper testing to avoid false doping accusations.

## Contribution

The study establishes a metabolic link between levonorgestrel and a prohibited substance metabolite, offering a solution to prevent false doping accusations.

## Key findings

- 18-methyl-19-noretiocholanolone was detected in all six participants after levonorgestrel ingestion.
- Levonorgestrel and its metabolite tetrahydronorgestrel were present in high concentrations up to 48 hours post-ingestion.
- The study confirms the need to test for levonorgestrel metabolites to avoid misinterpreting doping test results.

## Abstract

Athletes are explicitly responsible for everything they consume, which may be an issue when the metabolic pathways of prohibited and non‐prohibited compounds intersect. This was the case when 18‐methyl‐19‐noretiocholanolone, an 18‐methyl‐19‐nortestosterone metabolite, was detected in a sample of an athlete that had used an emergency contraceptive pill containing levonorgestrel.

Six women were recruited to this study to elucidate the link between 18‐methyl‐19‐noretiocholanolone and levonorgestrel. After providing a pre‐treatment urine sample, one tablet of NorLevo, 1.5 mg, was ingested and six additional urine samples were collected. The samples were analysed with GC–MS/MS after extraction and derivatisation.

In all six participants, 18‐methyl‐19‐noretiocholanolone could be detected at 1.5–2.5 ng/mL with a tmax of 2 h. The presence of 18‐methyl‐19‐noretiocholanolone was in all samples accompanied by levonorgestrel and its metabolite tetrahydronorgestrel, the latter being present at highest concentrations (60–300 ng/mL) up to 48 h post intake.

Conclusively, this study demonstrates a metabolic link between 18‐methyl‐19‐noretiocholanolone and levonorgestrel, confirming the need to verify the absence of levonorgestrel or its markers before reporting an adverse analytical finding.

Levonorgestrel, a hormonal contraceptive, metabolises to 18‐methyl‐19‐noretiocholanolone which is also the main metabolite of the prohibited substance 18‐methyl‐19‐nortestosterone. Analysing for levonorgestrel and/or tetrahydronorgestrel is essential to avoid misinterpreting 18‐methyl‐19‐noretiocholanolone findings.