The Horseracing Integrity and Welfare Unit has lifted the provisional suspension of George Weaver for a positive for metformin following a recommendation that the use of the substance in horses be studied further. The decision to review the drug will immediately affect Weaver and another trainer, Ramon Aguayo, who had a horse test positive for metformin five weeks ago but had yet to be issued a provisional suspension pending the confirmation of the drug in a split sample. Three other trainers have been issued suspensions for the drug under HIWU’s previous rules, ranging from two years to 75 days, and those decisions will not be affected. Metformin is a banned drug under HIWU’s rules, but it is commonly prescribed to diabetics to lower blood sugar levels and stimulate metabolism. Trainers, including Weaver, who have had horses test positive for the drug have said that the positives were the result of contamination from stable employees. “It’s bittersweet,” said Drew Mollica, Weaver’s attorney, on Tuesday. “I didn’t want George to go through this, but I do think that the exposure in this case can bring some sanity to this whole issue.” Weaver was suspended on May 16 as a result of his positive, which occurred in a horse who ran two months earlier. Mollica has said that the groom of the horse who tested positive had a prescription for metformin. In the past several weeks, Mollica has been pursuing an expedited hearing to argue for the lifting of the suspension. :: DRF Belmont Stakes Packages: Save up to 52% on PPs, Clocker Reports, Betting Strategies, and more “I’m grateful to see that they saw an inequity there, and they are going to investigate,” Mollica said. In a statement released on Tuesday, the Horseracing Integrity and Safety Authority, which devises the rules enforced by HIWU, said that it advised HIWU to “defer” the provisional suspensions until a committee of the Racing Medication and Testing Consortium can conduct a review of the science “relating to metformin." In equines, the drug has previously been studied as a treatment for weight loss in mares. The HISA statement stressed that metformin has “no recognized therapeutic use in horses” and that HISA was aware that “some horsemen may be using metformin to try and gain a performance advantage.” “However, there is limited scientific information available regarding the substance’s use in horses,” said Charles Scheeler, the chairman of HISA’s board of directors. “The HISA board feels that further expert analysis on the topic is necessary to determine if any refinement of HISA’s rules is appropriate.”    The RMTC’s review of the scientific literature is expected to take “a few months,” HISA said, after which HISA’s board will review the organization’s recommendations and approvals and “determine whether any policy changes regarding metformin should be submitted to the Federal Trade Commission for approval.” For the time being, any positive for metformin will still result in the disqualification of the horse, HISA said. The trainer of the horse will be charged with a deferred provisional suspension, HISA said, until the uncertainty over the current rules is resolved. Earlier this year, an arbitrator issued a two-year suspension to trainer Jonathan Wong after one of his horses tested positive for metformin after a race in 2023. The arbitrator wrote in her report that Wong had made “demonstrably false” and “untruthful” statements during his appeals hearing, including telling reporters that he was taking metformin. In another case, trainer Alex Lauer received a 75-day suspension after he provided evidence to HIWU that an employee could have been the source of the positive. Prior to the advent of HIWU, metformin was regulated as a Class B drug under the recommendations of the Association of Racing Commissioners International. Class B drugs do not have legitimate therapeutic uses in horses but are not as performance-enhancing as powerful stimulants or anabolic steroids. In the two years prior to HIWU taking over drug testing and enforcement, trainers Jimmy Baker and Wesley Ward each received 15-day suspensions for metformin positives in Kentucky. :: Want to learn more about handicapping and wagering? Check out DRF's Handicapping 101 and Wagering 101 pages.