The Anti-Doping and Medication Control (ADMC) program has proposed enforcing the screening limit of phenylbutazone at 300 ng/mL in blood, rather than the previously established screening limit of 200 ng/mL in blood. HISA will file Guidance with the Federal Trade Commission that will implement this change in the enforcement of the screening limit. The RMTC’s Scientific Advisory Committee (SAC) has been asked by industry stakeholders to review its withdrawal guidance of phenylbutazone based upon the updated proposed screening limit. Based on the updated screening limit of 300 ng/mL in blood and a single IV dose of 4.4 mg/kg, the SAC has reviewed all available data and is now recommending an updated withdrawal guidance of 72 hours for phenylbutazone. The RMTC’s Withdrawal Guidance of HISA’s ADMC Detection Times document will reflect those changes.