Which statement correctly describes steroid hormones?

• A. Solubility: lipid soluble; Carrier: present; Half-life: 30-90 minutes
• B. Solubility: water soluble; Carrier: none; Half-life: 10-30 minutes
• C. Solubility: water soluble; Carrier: present; Half-life: < 1 minute
• D. Solubility: lipid soluble; Carrier: absent; Half-life: 7-10 days

Answer: (A)

Steroid hormones are lipid-soluble molecules derived from cholesterol, so they freely cross cell membranes and exert their effects by binding to intracellular receptors to regulate gene transcription. In the bloodstream they are mostly carried by plasma binding proteins (such as albumin and specific steroid-binding globulins) because their lipophilicity makes them poorly soluble in water. This carrier binding creates a reservoir and slows down their clearance, giving them a longer circulating presence than water-soluble hormones. A typical circulating half-life for them is on the order of tens of minutes to a few hours, commonly described as about 30–90 minutes. This combination—lipid solubility, presence of carrier proteins, and a moderate half-life—best matches the described statement. Descriptions that claim water solubility, no carrier, or extremely short or extremely long half-lives do not align with how steroid hormones behave in the body.