Photograph of Yunnan Baiyao capsules. This proprietary Chinese herbal formulation is sometimes prescribed to veterinary patients as an adjunctive approach to preventing or slowing hemorrhage, especially for conditions such as hemangiosarcoma in dogs, shock and other causes of bleeding. However, the mechanisms of action, its level of effectiveness, and whether it is safe are unknown, because insufficient research exists. Moreover, not all products labeled as Yunnan Baiyao contain the same ingredients, and many aspects remain undisclosed, untested, and unregulated.