May 26. 2026 — Following up on an advisory distributed in January 2024, HIWU strongly advises horsemen to dispose of any variations of the herbal products that may be identified on the labels as Yunnan Paiyao, Yunnan Baiyao, and/or Baiyao. HIWU continues to find these supplements during searches despite the risks associated with them.
In testing various forms of these products, which are manufactured in the United States and abroad, both Banned Substances (e.g., boldione, glaucine, higenamine, and adenosine monophosphate) and Controlled Medications (e.g., ephedrine) have been reported in analyzed samples despite not being listed on the ingredient labels.
Continued use of these products may put horsemen at risk of a positive test.
As a reminder, supplements manufactured in the United States or elsewhere are not regulated by the United States Food and Drug Administration; horsemen and veterinarians use them at their own risk.
Additional resources are available on the HIWU website:
Dietary Supplements- What You Should Know
What’s the Scoop on Dietary Supplements?
By applying caution and conducting due diligence before purchasing or using dietary supplements, horsemen can ensure that they are doing their best to minimize the risk of unintentionally exposing their horses to Prohibited Substances.
For questions or to get in touch with HIWU’s Science team, please contactsciencesupport@hiwu.org.
About the Horseracing Integrity & Welfare Unit
The Horseracing Integrity & Welfare Unit (HIWU) was established in 2022 by Drug Free Sport International to administer the rules and enforcement mechanisms of the Horseracing Integrity and Safety Authority’s (HISA) Anti-Doping and Medication Control (ADMC) Program. The ADMC Program established a centralized testing and results management process that applies uniform penalties for violations efficiently and consistently across all American Thoroughbred racing jurisdictions that HISA governs. As the enforcement agency of the ADMC Program, HIWU oversees all testing processes, including the selection of horses to be tested, training of sample collection personnel, and chain-of-custody procedures. Additionally, HIWU is charged with industry/stakeholder education, laboratory accreditation, results management and adjudication, and investigations. For more information, please visit hiwu.org.
