WADA issues revised and New Technical Guidance on Dried Blood Spot Testing, Blood Transfusions, and Clomifene Analysis

Following a World Anti-Doping Agency (WADA) Executive Committee meeting on 11 September 2025, the agency has issued a revised Technical Document for Dried Blood Spots for Doping Control, a new Technical Document for the detection of an athlete’s illegal use of another person’s red blood cells, and a new Technical Letter concerning the analysis and reporting of clomifene, a substance which significantly increases testosterone levels. The documents and letter will come into effect from 1 January 2026. 

Regarding the first Technical Document, Dried Blood Spots (DBS) for Doping Control, major modifications have been made, such as: 

• Article 2.1 (DBS Collection Devices Requirements): This provides the requirements for DBS collection devices used by Anti-Doping Organisations. In addition, a comment to Article 2.1 has been added to clarify the number of Initial Testing Procedures that Testing Authorities may request on a single DBS collection device. 
• 2.2 (Acceptance of DBS Samples for Analysis): This Article has been modified to clarify that DBS Samples shall not be accepted for analysis if the laboratory does not have an Analytical Testing Procedure validated for the DBS collection device received. 
• 2.2.1 (DBS Samples with Irregularities): This Article has been modified to include additional examples of what should be considered irregularity for DBS samples specifically, and the steps that laboratories shall follow when irregularities are identified. 
• Articles 3.a-c include requirements for DBS “A” and “B” sample storage and describe how to store a DBS “B” sample during the “A” sample analysis if the “B” sample is in the same container as the “A” sample. 
• 6.1 (Short-term Storage of DBS Samples): This Article now changes the minimum period of storage of DBS samples from 3 to 6 months. 
• 6.2 (Long-term Storage of DBS Samples): This Article explains that all costs associated with long-term storage (i.e., beyond the 6 months established for the short-term storage) shall be borne by the Anti-Doping Organisation that requested the long-term storage. 

Regarding the second Technical Document - Detection of Homologous Blood Transfusion (HBT) by Flow Cytometry, this refers to the detection of an athlete’s illegal use of another person’s red blood cells. This Technical Document clarifies the requirements for HBT test method validation and accreditation. It also sets out the pre-analytical (sample preparation and storage) and analytical procedure requirements, and the criteria for interpretation and reporting of results. It also states that a second opinion is mandatory. 

The Technical Letter is titled: Clomifene - Instructions on the Analysis and Reporting of Clomifene Findings in Urine Samples. Clomifene is included in WADA’s Anti-Estrogenic Substances. Anti-oestrogen supplements can be abused in sport to optimise testosterone levels and increase muscle bulk. However, the substance may also be used as a fertility enhancer in hens to increase egg production. Therefore, the presence of the substance in athletes’ urine samples may be the result of food contamination from poultry meat and eggs. 

Therefore, the Technical Letter covers the analysis and reporting of clomifene findings. It also sets out a minimum reporting level which is the lowest concentration of a substance that a laboratory can accurately quantify and report for a given sample using a specific analytical method. This is for the clomifene parent compound only, meaning the initial drug molecule administered before undergoing changes like metabolism or conversion into metabolites. 

WADA’s official statement can be found here. 

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