it is a press release from USEF. I THINK the answer is yes, NATIONAL USEF endurance events (of which there has been only 1 ever sanctioned as I recall) would allow the use (they recommend a min 12 hour lead time). and say don't use it within 30 days of an FEI (CEI) event until FEI conducts a review of the drug.
I couldn't open the link you sent with the post, so please excuse me if this question is answered there.? By USEF approving this drug does this mean it will then be legal to use this during competition?? Also, when USEF approves a drug, is it approved for use in all disaplines?? I guess what I am asking is if this drug will be legal to use in USEF endurance events??