The steroid hormones are synthesized in the adrenal cortex, the gonads, and the placenta; are all derived from cholesterol and many are of clinical importance. Steroid hormones are synthesized in the mitochondria and smooth endoplasmic reticulum.

Where are steroids found naturally?

The natural steroid hormones are generally synthesized from cholesterol in the gonads and adrenal glands. These forms of hormones are lipids.

Where are most steroids found?

Hundreds of steroids are found in plants, animals and fungi. All steroids are manufactured in cells from the sterols lanosterol (opisthokonts) or cycloartenol (plants).