Prednisone: uses, dosage, side effects

last updated: Oct 13, 2021

6 min read

Every day, our immune systems operate to prevent infections and heal the damage that occurs in our bodies. Sometimes though, the immune system has a hard time distinguishing invaders or damaged cells from perfectly healthy ones, resulting in an accidental attack on normal cells called an autoimmune reaction (Rosenblum, 2015).

Other times, the immune system can recognize harmless foreign things (like pollen) as dangerous when they’re not. The subsequent attack can harm normal, healthy cells, which happens in certain allergic reactions (Rosenblum, 2015).

In either scenario, a healthcare provider may recommend a prescription drug called prednisone—a synthetic version of cortisol called a corticosteroid—to help limit these reactions  (Puckett, 2021).


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What is prednisone?

Prednisone is a prescription medication used to treat a very wide range of diseases. It’s a synthetic (laboratory-made) version of cortisol, a steroid hormone naturally produced in our bodies that plays an important role in a wide range of normal bodily processes. Most commonly, prednisone is used to reduce the activity of the immune system, thereby reducing processes like inflammation (Puckett, 2021). 

What does prednisone treat?

Steroids like prednisone limit immune reactions in a variety of conditions. How the medication works is a little bit different in each case. The following is a list of some of the most common conditions for which healthcare providers prescribe prednisone as a treatment (FDA, n.d.): 

  • Asthma: In people with asthma, the immune system is triggered to attack after a person is exposed to something that isn’t actually harmful, resulting in inflammation and swelling in the respiratory tract that makes it difficult to breathe. Steroids like prednisone can help alleviate this inflammation, making it easier to breathe. 

  • Autoimmune diseases like lupus, myasthenia gravis, rheumatoid arthritis, and others are characterized by the immune system attacking different areas of the body. 

  • Digestive disorders like Crohn’s disease and ulcerative colitis

  • Adrenocorticoid deficiency: In this condition, the body doesn’t produce enough cortisol. Patients with adrenocorticoid deficiency are treated with medications like prednisone, which acts like cortisol in the body. 

  • Inflammatory diseases like gout; a condition characterized by painful swelling in the joints and associated with increased levels of a substance called uric acid. 

  • Prevention of allergic reactions such as in people who have previously experienced an allergic reaction to iodine injected before CT scans. 

  • Graft-versus-host (GVH) disease: Certain organ transplants can come with immune cells from the donor. Those immune cells can sometimes attack the recipient’s body, and steroids like prednisone can help prevent these kinds of attacks. 

  • Organ rejection: In patients who receive organs, their immune system can recognize the donated organs as foreign and attack them, causing damage. Treatment with steroids can suppress this reaction and prevent organ rejection.

  • Certain types of cancer like prostate cancer and multiple myeloma (a kind of blood cancer).

  • Covid-19: Steroids are frequently used off-label in Covid patients who are in critical condition. Research has shown that severely ill, hospitalized patients requiring treatment with supplemental oxygen had a lower risk of dying from Covid-19 after treatment with a steroid medication called dexamethasone than those who did not receive the drug. Dexamethasone is a strong steroid and the drug of choice here, but if it’s not available, prednisone in a higher dose works too. Researchers believe that steroids work by reducing immune activity, which, although directed at controlling the virus, actually causes damage to healthy cells, like those in the lungs (NIH, 2021). 

Prednisone side effects

While prednisone and other steroid medications are useful in treating many diseases, they aren’t without side effects. The occurrence of side effects increases with higher doses and long-term use. Side effects also vary based on the route of administration (injection, pills taken by mouth, inhaled mist/powder) (Huscher, 2008). 

Common side effects of treatment with prednisone include:

  • Thrush: Overgrowth of candida yeast that typically appears on the tongue or the sides of the mouth in patients taking corticosteroids. Thrush is most common when the steroids are inhaled from an inhaler. The use of a device called a spacer, which delivers the drug further into the airways and protects the mouth, is usually effective for preventing the condition (Erdoğan, 2019). 

  • Weight gain and swelling: Corticosteroids affect how your body utilizes calories (your metabolism) and how your body distributes fat. Long-term treatment with steroid medications can cause weight gain, particularly in the abdomen. In addition, prednisone affects how your kidneys handle electrolytes like salt. As a result, treatment with these steroids can cause fluid retention and swelling. These effects are reversible and typically subside after your treatment is stopped (Kapugi, 2019). 

  • Cataracts: Even at very low doses, long-term treatment with corticosteroids can cause a condition called cataracts, a vision problem characterized by clouding in the normally clear lens in the eye, making it difficult to see. Treatment involves a routine surgical procedure to replace the lens (James, 2007). 

  • Bone loss: Even at low doses and especially during the first few months of treatment, research has shown significant bone loss (osteoporosis) and an increased risk of bone fractures in patients treated with corticosteroids. The risk of fractures increases significantly during the first 3–6 months of treatment. However, this risk is reduced after treatment is withdrawn (Staa, 2002). 

  • Increased risk of infection: Because prednisone tamps down immune function, patients taking steroids, especially for long periods, are more prone to developing infections and have a more difficult time recovering from them (Puckett, 2021). 

Other reported adverse effects include high blood pressure, impaired wound healing, easy bruising, muscle weakness, sleep disturbances, headache, dizziness, acne, mood changes/mood swings, behavioral/thought disturbances, and more (FDA, n.d.). 

The side effects and their severity depend on how high your dose is and how long you take steroids. This list is not exhaustive, and you may experience other side effects while taking prednisone. If you experience any side effects or reactions when taking corticosteroids, inform your healthcare provider (FDA, n.d.). 

Coming off of prednisone 

While occasional or short-term courses of treatment with corticosteroids like prednisone can be stopped when the treatment is no longer needed, patients receiving long-term treatment or high doses should have their dosages reduced gradually over a period of time by a healthcare professional when it’s time to stop the medication to reduce the risk of serious side effects (FDA, n.d.). 

The body normally produces its own steroid hormones, and when you take steroid medications, your body recognizes the presence of these synthetic steroids and reduces the production of its own. If you stop taking your medication suddenly, your body will suddenly have very low levels of steroid hormones which can affect your blood pressure and other crucial functions.

Lowering the dosage gradually prevents complications of steroid withdrawal, which can be dangerous and even life-threatening. If you experience side effects while taking your medication, do not stop taking it without consulting your healthcare provider (FDA, n.d.). 

There have been isolated reports of allergic reactions to corticosteroids. Do not take prednisone if you have ever had an allergic reaction to steroid medications. In addition, those who have a history of gastric ulcers or who have recently had surgery on their digestive system should use prednisone with caution as it can increase the risk of perforations (holes) in the digestive tract in these individuals (FDA, n.d.). 

Drug interactions, warnings, precautions

If you have any of the following conditions, consult with your healthcare provider before starting treatment with prednisone (FDA, n.d.):

  • Those with herpes simplex infections in the eye

  • Individuals who have recently received live or live-attenuated vaccines: If you have recently received any vaccine, discuss this with your healthcare provider before starting treatment with prednisone. 

  • Anyone with a widespread fungal infection 

  • Those who may have had tuberculosis (TB) or are not sure if they have been exposed to TB

  • Individuals with liver disease or other liver or kidney problems

  • Those with thyroid conditions as corticosteroids may disrupt thyroid function

  • People with diabetes should use steroids only under close monitoring by a healthcare provider as the medication can disrupt blood sugar levels.

This list is not exhaustive. Discuss your medical history and any medications or supplements you take with your healthcare provider before starting any new medication.

There is evidence that taking prednisone can prolong viral illnesses or mask signs of certain types of infections. Avoiding exposure to infections such as measles and chickenpox is important when taking corticosteroids as prednisone is immunosuppressive. If you need vaccinations while receiving treatment with corticosteroids, inform your healthcare provider (FDA, n.d.). 

Taking prednisone while pregnant

If you are pregnant or may become pregnant, consult with your healthcare provider before starting treatment with corticosteroids. These medications have been shown to cross the placenta and reach the fetal blood, but the drug is found in much lower levels in the fetus than in the mother. 

Still, some evidence shows that taking steroids during pregnancy can affect the fetus, especially during the first trimester (first three months) of pregnancy. Also, taking corticosteroids during pregnancy can increase the risk of maternal gestational diabetes, which is diabetes that develops during pregnancy. If you need to take steroids during pregnancy, your healthcare provider will weigh the risks of using the medication against the risks of your underlying condition and may prescribe the lowest effective dose of steroids to avoid complications (Leachman, 2006). 

Research has shown that prednisone taken by a nursing mother enters breast milk. According to the World Health Organization (WHO), it should not affect a nursing infant when taken in regular doses. That said, your healthcare provider may recommend waiting four hours after taking prednisone before nursing to reduce exposure to the nursing infant (Leachman, 2006).

If you have questions or concerns about taking prednisone, speak with your healthcare provider who can provide you with accurate medical advice. They can go through your medical history and come up with a treatment plan that works for you.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

October 13, 2021

Written by

Yael Cooperman, MD

Fact checked by

Mike Bohl, MD, MPH, ALM

About the medical reviewers

Yael Cooperman is a physician and works as a Senior Manager, Medical Content & Education at Ro.

Dr. Mike is a licensed physician and a former Director, Medical Content & Education at Ro.