Steroids, or corticosteroids, are a group of medications that resemble a hormone in your body called cortisol. They reduce inflammation and are used to treat a wide range of conditions, including:

Regularly taking steroids can weaken your immune system and increase your risk of developing COVID-19 or more severe illness.

Corticosteroids are different than anabolic steroids, which are drugs that replicate the hormone testosterone. Although anabolic steroids do have legitimate medical uses, people often use them recreationally to build muscle and improve sports performance.

The use of anabolic steroids has also been linked to poorer COVID-19 outcomes.

Keep reading to learn how steroids work and how they affect your immune system.

Corticosteroids are human-made drugs that replicate the hormone cortisol. Your adrenal glands, located at the top of your kidneys, produce cortisol.

Corticosteroids are among the most widely prescribed drugs worldwide. Nearly 1 percent of the global population uses long-term corticosteroid therapy as treatment.

Among the conditions they treat include:

Corticosteroids reduce inflammation in your body by binding to receptors that suppress your immune system’s activity.

According to the Centers for Disease Control and Prevention (CDC), long-term steroid use can compromise your immune system and make you more likely to get sick from COVID-19 or other respiratory diseases.

Long-term (or chronic) corticosteroid use is associated with:

  • increased risk of upper respiratory tract infections
  • increased viral replication
  • delayed viral clearance
  • increased risk of secondary infection

In a previous study from 2020, researchers found that taking over 10 milligrams of the steroid prednisone per day was associated with a 2.05 times higher chance of hospitalization in people with rheumatoid arthritis.

Some steroids can potentially cause the antiviral drug remdesivir to be removed from the body more quickly. This makes the drug less effective at treating COVID-19.

Athletes and bodybuilders widely abuse anabolic steroids to improve appearance or performance. The use of anabolic steroids can alter the immune system and increase the risk of infection.

A 2022 study found that current anabolic steroid use is a risk factor for COVID-19 severity.

In the study, current steroid use was associated with five times a greater chance of contracting COVID-19. Current anabolic steroid use was also associated with a higher chance of developing moderate to severe COVID-19.

If you have a medical condition that increases your chances of getting very sick with COVID-19, the CDC recommends talking to a healthcare professional about how to best protect yourself.

Doctors decide whether to continue corticosteroid treatment on a case-by-case basis. Your doctor can give you the best idea about whether you should stop taking steroids or lower your dosage. Up to 90 percent of people who take steroids longer than 60 days develop side effects.

You can also protect yourself by making sure your COVID-19 vaccines are up to date. You may be eligible for additional boosters if you’re considered immunosuppressed.

Other ways you can protect yourself include:

  • Wear a KN95 or N95 mask in public areas or when around people who are sick.
  • Stay 6 feet away from other people.
  • Avoid close contact with people who are sick.
  • Avoid poorly ventilated or crowded spaces.
  • Wash your hands frequently and for at least 20 seconds.

Here are some of the frequently asked questions people have about steroids and COVID-19.

Does risk change depending on how I take steroids?

Oral or injected steroids are more likely to cause side effects such as immunosuppression than inhaled steroids or topical steroids. Side effects tend to increase with the dose and the longer you take them.

Inhaled steroids generally cause fewer and milder side effects than oral corticosteroids.

Do steroids interfere with the COVID-19 vaccine?

According to a 2022 study, there’s ongoing discussion on whether steroids decrease vaccine efficiency despite no direct evidence that they do.

In a 2021 review of studies, five out of six studies found evidence of successful vaccination in people taking steroids.

They concluded that based on the current evidence, it’s reasonable to delay steroid injections for chronic pain for 1 to 2 weeks after vaccination, and to delay vaccination for 2 weeks after procedures involving steroids.

Can steroids be used to treat COVID-19?

According to the National Institutes of Health’s COVID-19 Treatment Guidelines, multiple high-quality studies suggest that corticosteroid therapy improves outcomes in people with COVID-19 who require oxygen therapy. This may be because they reduce the inflammatory reaction that leads to lung injury and dysfunction.

The most widely studied corticosteroid for treating COVID-19 is dexamethasone. Researchers have also studied other steroids like hydrocortisone and methylprednisolone, but evidence to back the use of these medications isn’t as strong.

A 2022 study linked steroids to better outcomes in younger people but not older people.

Some studies have found evidence that steroids increase the risk of COVID-19-associated pulmonary aspergilloses (CAPA) in intensive care patients. CAPA is a fungal infection of the lungs that can increase the risk of mortality.

Steroids treat a wide variety of conditions. They work by reducing inflammation and suppressing your immune system. Taking steroids, especially in high doses, may make you more prone to COVID-19 infection.

Your doctor can best advise you on whether you should lower or reduce your dose. You can also reduce your chances of getting COVID-19 by taking preventive measures like washing your hands regularly and staying up to date with your vaccines.