Cortisol vs cortisone: what is the difference?

Cortisol and cortisone sound alike and are close chemical relatives, but they do different things. Cortisol is the active hormone your adrenal glands release. Cortisone is an inactive form that your body can turn into cortisol, and cortisol into cortisone, as needed.

The words around them cause more confusion: steroid, glucocorticoid, corticosteroid. This page sorts out all of them. It explains what the terms mean. It doesn’t cover treatment or dosing.

Cortisol

One blood draw for one cortisol result. It can’t diagnose or rule out an adrenal condition by itself.

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Cortisol and cortisone side by side

	Cortisol	Cortisone
What it is	The active hormone	An inactive form
Where it comes from	Made by the adrenal glands	Not made in the adrenal glands. Produced from cortisol, mostly in the kidney and gut
Level in blood	Higher	About 4 times lower than cortisol
Level in saliva	Lower	About 6 times higher than cortisol

The blood and saliva figures come from a 2024 review in Endocrine Reviews (source). They are group averages, not targets, and they say nothing about whether your own result is typical.

How the body converts one to the other

The conversion runs in both directions, and the enzymes that do it are called 11 beta-hydroxysteroid dehydrogenases, or 11 beta-HSD for short (Endocrine Reviews, 2024).

• 11 beta-HSD type 2 turns active cortisol into inactive cortisone. It is active in places such as the kidney.
• 11 beta-HSD type 1 turns cortisone back into cortisol. It is most active in the liver, fat tissue and skeletal muscle. The review estimates that this reactivation contributes 30 to 40 percent of daily cortisol production.

This arrangement lets tissues adjust how much active hormone reaches their own cells, which in turn affects feedback to the brain’s control of the adrenal glands. A 2017 review describes the same switch in the brain, where the enzyme regenerates active cortisol (Endocrine Reviews, 2017).

You don’t control this process, and you can’t tell how it is working from how you feel.

Cortisol is a steroid, a glucocorticoid and a corticosteroid

These words overlap.

• Steroid hormone. Cortisol is made from cholesterol (Endocrine Reviews, 2017). A 2018 review says glucocorticoids are steroids that cross cell membranes easily and can reach almost any cell in the body (Front Behav Neurosci, 2018). The adrenal glands make cortisol and aldosterone, along with adrenaline, noradrenaline and hormones the body uses to make sex hormones (MedlinePlus).
• Glucocorticoid. This is cortisol’s class. The same review calls cortisol the main glucocorticoid in humans. NIDDK describes glucocorticoid medicines as similar to cortisol.
• Corticosteroid. MedlinePlus calls these medicines corticosteroids and says they are similar to hormones the adrenal glands make. They reduce inflammation and affect the immune system.

Don’t confuse these with anabolic steroids, which MedlinePlus describes as a different group of steroids that can have harmful effects.

When people say they “take steroids” for asthma, arthritis or a skin condition, they usually mean corticosteroids. If you take one, never stop it or change the dose on your own. NIDDK says suddenly stopping corticosteroids that were taken for a long time is the most common cause of adrenal insufficiency, so ask your prescriber.

Cortisol vs corticosterone

Corticosterone is a related hormone. In humans cortisol is the main glucocorticoid. In rodents the equivalent is corticosterone (Front Behav Neurosci, 2018). The 2024 Endocrine Reviews paper adds that older cortisol lab methods were not specific and measured both cortisol and corticosterone.

Cortisol vs fludrocortisone and aldosterone

Another name that turns up is fludrocortisone. It belongs to a different job. Your adrenal glands also make aldosterone, a hormone involved in sodium and fluid balance. NIDDK says that when the adrenal glands aren’t making aldosterone, people take a medicine called fludrocortisone to help balance sodium and fluids, and that cortisol is replaced separately with a corticosteroid. People with secondary adrenal insufficiency usually make enough aldosterone and so don’t need it.

That is information about how the pieces fit together. It isn’t advice. Decisions about these medicines belong to the prescriber. See low cortisol for the condition itself.

Does a cortisol test measure cortisone?

A standard cortisol blood test reports cortisol. Cortisone is measured less often, for example in some saliva tests used in research and specialist testing. A 2020 study measured late-night saliva cortisol and cortisone in 1,453 samples from 705 people with suspected Cushing’s syndrome. Most people with at least one raised saliva result did not turn out to have Cushing’s syndrome, and the authors concluded that adding cortisone didn’t improve the sensitivity of the saliva cortisol test (PubMed).

That is why a single saliva or blood number can’t settle the question. Cushing’s syndrome and adrenal insufficiency are diagnosed by a clinician using more than one test. The tests used for Cushing’s syndrome include late-night saliva, a 24-hour urine collection and a dexamethasone suppression test. See the cortisol test guide and free and total cortisol for how the main tests differ.

Questions people ask

Is cortisone a stress hormone?

Not directly. Cortisol is the one called the stress hormone. Cortisone is the inactive form that the body can convert to cortisol.

Is the hormone cortisol the same as a cortisone injection?

No. The hormone is what your body makes. A joint injection of a glucocorticoid is a medicine, and NIDDK notes that glucocorticoids are often injected into a joint for pain. Whether and how to use one is a decision for a clinician.

Is cortisol a steroid?

Yes. Cortisol is a steroid hormone and a glucocorticoid. It is not an anabolic steroid.

Keep reading

• What is cortisol?

  The hormone, its jobs and why the level changes.

• The HPA axis

  How the brain controls cortisol through ACTH.

• Free and total cortisol

  Why carrier proteins matter for a blood result.

• Saliva, urine and hair tests

  What each sample type can and can't show.