WADA publishes revised Technical Document; new Technical Document and new Technical Letter

Further to decisions taken by the World Anti-Doping Agency’s (WADA’s) Executive Committee (ExCo) when they met on 11 September 2025, WADA is pleased to publish:  

• a revised version of the Technical Document for Dried Blood Spots for Doping Control (TD2026DBS); 
• a new Technical Document for the detection of Homologous Blood Transfusion (HBT) by flow cytometry (TD2026HBT); and 
• a new Technical Letter related to the analysis and reporting of clomiphene (TL26). 

The TDs and TL will come into effect on 1 January 2026.  

TD2026DBS – Dried Blood Spots (DBS) for Doping Control – Requirements and Procedures for Analytical Testing and Sample Storage 

This TD was subject to stakeholder consultation in January and June 2025. This revision features improvements to the formatting, structure, and clarity of the document, as well as  some major modifications which are listed below:   

• Article 2.1 (DBS Collection Devices Requirements): This new article has been included to provide the requirements for DBS collection devices used by Anti-Doping Organizations. A more comprehensive list of requirements will be provided in the upcoming 2027 International Standard for Testing.  
• Article 2.2 (Acceptance of DBS Samples for Analysis): This article has been modified to clarify that samples should not be accepted for analysis if a laboratory does not have a validated analytical testing procedure for the DBS collection device received, and to illustrate irregularities applicable to DBS Samples specifically, and the steps that laboratories should follow when the irregularities are identified. 
• Article 4.0 (Selection and Validation of Analytical Testing Procedures): This article has been modified with the addition of Article 4.a, which provides laboratory guidance on the validation and implementation of the minimum testing menu for all relevant DBS analytical testing procedures and target analytes – as described in the Minimum Harmonized DBS Testing Menu reported in Annex A of this TD. 
• Article 6.0 (Storage of DBS Samples): This article now reflects the change in the minimum period of storage of DBS Samples from three (3) to six (6) months. 

TD2026HBT – Detection of Homologous Blood Transfusion by Flow Cytometry 

This new TD has been produced by WADA’s HBT Working Group to harmonize the analysis for detection of Homologous Blood Transfusion (HBT) in whole blood by flow cytometry. 

The TD includes requirements for HBT test method validation and accreditation; pre-analytical (sample preparation and storage) and analytical procedure requirements; criteria for interpretation and reporting of results; and, a mandatory second opinion process before reporting HBT findings as an Adverse Analytical Finding or Atypical Finding. 

TL26 Clomifene – Instructions on the Analysis and Reporting of Clomifene Findings in Urine Samples  

Clomifene (included in WADA’s Anti-Estrogenic Substances) is prohibited at all times (in- and out-of-competition). However, clomifene may be used as a fertility enhancer in domesticated hens to increase egg production. Therefore, the presence of clomifene and/or its metabolites in urine samples may result from food contamination, as clomifene residues may be present in contaminated poultry meat and eggs consumed by athletes.  

Therefore, TL26 includes instructions on the analysis and reporting of clomifene findings in urine samples, including the establishment of a minimum reporting level (MRL), which is applicable to the clomifene parent compound only.  

About WADA’s Technical Letters and Documents  

Under the International Standard for Laboratories, WADA’s TLs and TDs provide direction to WADA-accredited laboratories, WADA-approved laboratories for the Athlete Biological Passport, and other stakeholders. TLs are concerned with issues of analysis, interpretation, and reporting of results for specific Prohibited Substance(s) and/or Prohibited Method(s) or with the application of specific Laboratory procedures, whereas TDs are concerned with technical and procedural issues.  

As part of WADA’s mandate to enhance anti-doping activities under the World Anti-Doping Code, TLs and TDs are occasionally revised to reflect scientific and technological advances in the performance of anti-doping tests and the reporting of test results. They are revised and refined in consultation with WADA stakeholders.  

WADA’s TD index and TL index are available on WADA’s website.  

Should you have any questions regarding the above, we invite you to contact WADA’s Science Department at: science@wada-ama.org.