Cholesterol is the most common steroid in the body. It is a precursor to vitamin D and many steroid hormones, including testosterone, estrogen, and cortisol.

Cholesterol belongs in the family of steroids because it shares a similar chemical structure.

This article discusses cholesterol and its importance and role in the body. It also explores the relationship between cholesterols, steroids, and lipids.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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Cholesterol is a type of lipid or fat within the body. The liver makes all the cholesterol the body needs, but a person can also obtain it from animal food sources, such as meat, cheese, and eggs.

This waxy substance is a primary component of the cell membrane, a thin layer of tissue that surrounds and protects every living cell. The body uses cholesterol as a precursor to making vitamin D, bile acid, and steroid hormones.

Cholesterol present in the bloodstream can have protective effects, as high-density lipoprotein (HDL), or adverse effects, as low-density lipoprotein (LDL), on cardiovascular health, depending on how it moves within lipoproteins.

Excess LDL cholesterol in a person’s blood circulation can lead to the development of atherosclerosis and heart disease.

Learn more about cholesterol and where it comes from.

Steroids are a type of lipids with a distinct chemical structure. While they are dissimilar to other lipids in structure, scientists classify them as lipids because they are hydrophobic — meaning they repel water — and insoluble in water.

All steroids have four linked carbon rings. From this basic component, various functional groups may attach to form different types of steroids.

In the body, steroid hormones all derive from cholesterol. There are different classes of steroids grouped according to which receptors in the body they bind to. These include:

  • Glucocorticoids: This hormone regulates blood glucose levels by preserving plasma glucose for the brain during stress for optimal brain function. Examples include cortisone.
  • Mineralocorticoids: This hormone regulates salt and water imbalances in the body. Examples include aldosterone.
  • Estrogens: This hormone promotes sexual and reproductive development in females.
  • Androgens: This hormone is crucial for reproductive and sexual function in males.
  • Progestagens: These hormones are active during pregnancy and help maintain it.

Scientists can also manufacture synthetic steroids, such as anabolic steroids and birth control pills.

Cholesterol is a steroid because it shares the chemical structure of four fused carbon rings with other steroids.

Specifically, it is a sterol, which is a class of lipid with an alcohol (hydroxyl) or -OH group. This makes it a molecule with both hydrophobic and hydrophilic — meaning water-attracting — properties.

Learn more about the structure of cholesterol.

Sterols are present in animals and plants. Plant sterols are present in:

Lipids are a category of molecules comprising fats and oils. There are a variety of lipids in the body, with different structures and diverse roles.

Chemically, lipids comprise chains of carbon and hydrogen atoms. They are not water soluble, meaning they do not mix well in water but are soluble in organic solvents.

They play a crucial role in many vital processes in the body and are diverse in their structure. There are four main groups of lipids:

  • fatty acids
  • glycerides or glycerol-containing lipids
  • nonglyceride lipids
  • complex lipids

A steroid is a type of nonglyceride lipid, along with triglycerides, phospholipids, and sterols.

Learn more on cholesterol as a lipid here.

Cholesterol is an important steroid that the body produces.

The body needs a small amount of cholesterol to perform vital body functions, including:

Cholesterol cannot travel through the blood by itself and needs to attach to proteins to move through the bloodstream. Different types of lipoproteins have different purposes. Two main types include:

  • LDL cholesterol: This type makes up most of the body’s cholesterol. Health professionals sometimes refer to it as “bad” cholesterol because it collects in blood vessels and causes plaque buildup.
  • HDL cholesterol: Health experts also call this type “good cholesterol” because it carries cholesterol to the liver, which removes it from the body.

Learn more about the differences between LDL and HDL cholesterol here.

Too much “bad” cholesterol or insufficient “good” cholesterol increases the risk of cholesterol building up in the inner walls of arteries. This can narrow and harden arteries, causing atherosclerosis.

A stroke or heart attack may occur if a blood clot forms and blocks a blood vessel or dislodges, travels, and blocks other blood vessels.

The National Heart, Lung, and Blood Institute provides the optimal cholesterol levels for individuals according to their age and gender, in milligrams per deciliter (mg/dl).

Type of cholesterolAnyone 19 or youngerMales aged 20 or overFemales aged 20 or over
Total cholesterolless than 170 mg/dl125–200 mg/dl125–200 mg/dl
non-HDLless than 120 mg/dlless than 130 mg/dlless than 130 mg/dl
LDLless than 100 mg/dlless than 100 mg/dlless than 100 mg/dl
HDLmore than 45 mg/dl40 mg/dl or higher50 mg/dl or higher

Learn more about cholesterol levels by age here.

Someone with high cholesterol will usually not feel any signs or symptoms. It is crucial to get a cholesterol test or lipid profile to see the levels of each specific cholesterol in a person’s blood.

The Centers for Disease Control and Prevention (CDC) recommend that:

  • healthy adults undergo testing every 4–6 years
  • people undergo testing more frequently if they have heart disease, a family history of high cholesterol, or risk factors for cardiovascular disease such as obesity and high blood pressure
  • individuals test at least once between ages 9 and 11 and again between ages 17 and 21

Here are some answers to frequently asked questions about steroids and cholesterol.

Do steroids derive from cholesterol?

Cholesterol is the precursor for steroid hormones in the human body. Aside from steroids, cholesterol is also crucial in making vitamin D and bile salts.

Is cholesterol a steroid or alcohol?

Cholesterol belongs to a group called sterols or steroid alcohols. A sterol is a subgroup of steroids. It is a type of lipid with an -OH (alcohol) group.

Is cholesterol a protein?

Cholesterol is a fatty substance and not a protein. However, cholesterol does not mix with water and blood, so the body packages cholesterol with proteins. It then travels across the bloodstream as protein-covered particles called lipoproteins.

Cholesterol is a type of steroid the body produces to perform many vital functions.

It is the precursor to many steroid hormones, including sex hormones and hormones necessary for glucose metabolism and ion balances in the body.

While the body needs cholesterol, excess levels of the substance may put a person at risk of cardiovascular diseases.