All of the following are androgens except?

Regu-Mate is not classified as an androgen. It is actually a brand name for the drug altrenogest, which is a synthetic progestin used primarily in horses to regulate breeding cycles and manage reproductive issues. Unlike androgens, which are steroid hormones that promote the development of male characteristics and are often used in bodybuilding or veterinary contexts to enhance muscle growth and performance, Regu-Mate serves a different purpose entirely, being involved in reproductive hormone management.

In contrast, Winstrol-v, Equipoise, and Deca-durabolin are all anabolic steroids with androgenic properties, meaning they promote muscle growth and other masculine traits. Winstrol-v (stanozolol) is known for its use in both veterinary and human medicine, Equipoise (boldenone undecylenate) is commonly used in equine medicine, and Deca-durabolin (nandrolone decanoate) has applications in veterinary medicine to enhance weight gain and muscle development in animals. Each of these compounds directly contributes to the increase of anabolic activity, which is characteristic of androgens.