Nandrolone Decanoate can interact with progesterone receptors causing some side effects. Therefore, Eminence Labs Deca is much safer than testosterone as it has minimal drug predisposition to aromatize. Nandrolone Decanoate belongs to the AAS class II group, consisting of 19-nortestosterone derivatives. AAS is a large group of fast-growing synthetic androgens used both clinically and illegally.