Commentary below on evidence of anaphylaxis and sudden death from use of medroxyprogesterone acetate, the compounded form of Depo-Provera. This drug was originally thought to control estrus in mares; however, research has shown that it does not and is instead being misused as a tranquilizer on horses of both sexes. The first question that needs to be answered is, what is wrong that you would need a psychoactive drug to ride your horse in the first place?
https://www.chronofhorse.com/article/side-effects-may-include-sudden-death?fbclid=IwAR0dRnR2GCHIjxIO2Oi4k7pcXR_HykENFb3fL0NmF7HAbWyCxTQ4OYzv8pg
Comments