Trenbolone Acetate (Tren A) is a fast-acting, highly potent anabolic-androgenic steroid, often used in veterinary medicine and misused for performance enhancement in sports. It is a powerful derivative of nandrolone (a progestogen) and acts as an androgen ester, commonly administered via intramuscular injection. It is a controlled substance, classified as Class C in the UK and Schedule III in the US.