Steroid hormones, including testosterone, are classified as lipids. Specifically, they belong to a subgroup known as steroids, which are characterized by their structure that includes four fused carbon rings.
Cholesterol serves as a precursor for these hormones, and since both cholesterol and steroid hormones are lipophilic (fat-soluble), they fall under the broader category of macromolecules known as lipids. Lipids play significant roles in biological systems, including energy storage, membrane structure, and signaling functions as hormones.