Steroid hormones are cholesterol based endocrine signalling molecules consisting of adrenocorticoids, glucocorticoids and gonadocorticoids released by the Adrenal gland.
The most common hormones released are Aldosterone (regulation of electrolytes in the ECF), Cortisol (regulation of cellular metabolism and stress) and Testosterone (predominently male sex hormones and some female sex hormones). Steroids are lipid soluble and diffuse into cells through the membrane binding with and activating a receptor that transports the hormone into the nucleus where it binds with a specific DNA-receptor protein turning on its target gene and initiating the transcription process for the manufacture of a protein such as an enzyme. (Marieb, 2001)
Testosterone Molecule (Theodora.com, 2014)