The United States Equestrian Federation (USEF) and Equine Canada have implemented new regulations surrounding the drugs γ-aminobutyric (GABA) and vedaprofen, respectively.

Recently, reports of the use of a product called Carolina Gold have been brought to the USEF Equine Drugs and Medications Program. One of the principal constituents of the product, GABA, is an inhibitory neurotransmitter.

While initially not considered a forbidden substance, the use of GABA as a "calming supplement" does violate the spirit and intent of the Equine Drugs and Medications Rule. During recent research and administration trials involving Carolina Gold, many adverse reactions were documented. The nature of these reactions has prompted immediate action from the USEF Equine Drugs and Medications Program.

Effective immediately, Carolina Gold or any other product containing GABA is considered a forbidden substance under USEF rules. Further, because there are no recognized medical uses for this substance, the use of a Medication Report Form to report its administration is not applicable