How long is the immune system compromised after a steroid injection?

October 6, 2025 •

4 min read

According to research, a single local steroid injection into a joint or near the spine can cause mildly lowered immune defenses for approximately 1 to 4 weeks. This temporary compromise is a known pharmacological effect, varying based on the steroid type, dose, and individual health factors.

Quick Summary

The duration of immune system compromise after a steroid injection is typically a few weeks, though it varies by dosage and location. Steroids suppress immune cells and cytokines, with effects potentially lasting longer with higher doses or systemic exposure. Minimizing infection risk is crucial during this period.

Key Points

Duration Varies: After a localized steroid injection, the immune system is typically mildly compromised for 1 to 4 weeks, though this duration can extend depending on the dose and individual.
Dose and Site Matter: Higher doses and injections into the spine (epidural) or joints can lead to more significant or prolonged immunosuppression.
Immune Cell and Cytokine Suppression: Steroids reduce the function of key immune cells like lymphocytes and monocytes, and suppress inflammatory cytokines, disrupting both innate and adaptive immunity.
HPA Axis Impact: The Hypothalamic-Pituitary-Adrenal (HPA) axis can be suppressed for weeks after an injection, which may correlate with a longer-lasting immunosuppressive state.
Manage Infection Risk: To reduce risk, avoid crowded places and contact with sick individuals, practice good hygiene, and lead a healthy lifestyle during the recovery period.
Adrenal Insufficiency Warning: After multiple or high-dose injections, a steroid card may be necessary to alert other healthcare providers to the risk of adrenal insufficiency, a potentially life-threatening condition.
Different Routes, Different Effects: The degree of immune compromise is generally less intense for localized injections compared to systemic (oral or IV) steroid treatments.

Understanding the Immune-Suppressing Effects of Steroid Injections

Steroid injections, also known as corticosteroid injections, are a common medical procedure used to reduce inflammation and relieve pain associated with conditions like arthritis, tendinitis, and bursitis. While highly effective for targeted relief, these injections can have systemic effects, including a temporary suppression of the immune system. The duration and degree of this compromise depend on several factors, including the type and dose of the steroid, the injection site, and individual health considerations. Understanding these factors is crucial for minimizing risks and managing post-injection care effectively.

The Mechanism Behind Immunosuppression

Corticosteroids are synthetic versions of cortisol, a hormone naturally produced by the adrenal glands. When administered, they mimic and amplify cortisol's anti-inflammatory actions by disrupting various components of the immune response. This process involves several key mechanisms:

Suppression of Immune Cells: Steroids impair the function and migration of vital immune cells, including neutrophils, macrophages, monocytes, and lymphocytes. This means the body is less equipped to mount a robust defense against pathogens.
Reduction of Cytokines: Corticosteroids suppress the release of cytokines, which are chemical messengers that coordinate the immune response. A single injection can suppress these messengers for over 96 hours, potentially increasing susceptibility to viral infections.
Hypothalamic-Pituitary-Adrenal (HPA) Axis Suppression: Exogenous steroids can suppress the HPA axis, which controls the body's natural production of cortisol. This suppression can last for 2–4 weeks or longer, potentially indicating a longer-lasting immunosuppressive effect.

How Long is the Immune System Compromised?

For a single, localized injection (e.g., joint or epidural), the immune-suppressing effect is typically mild and transient, though it can still be significant enough to warrant caution. The duration of this mild compromise often ranges from one to four weeks, though higher doses or repeated injections can extend this period. Studies have shown that some systemic immune effects, such as suppression of specific cells and cytokines, occur within days and weeks of an injection.

Factors Influencing the Duration of Immunosuppression:

Dosage: Higher doses of corticosteroids are associated with a more pronounced and potentially longer-lasting suppression of the immune system.
Injection Site: While local injections aim for targeted treatment, some medication is absorbed systemically. Epidural injections have a well-documented systemic effect, and intra-articular injections can also influence systemic immune function.
Individual Health: A person's overall health, including comorbidities like diabetes, can affect the magnitude and duration of HPA axis suppression and other systemic effects.
Frequency: Receiving multiple injections in a short period or over an extended time can prolong the immunosuppressive state. Some sources suggest that if three injections are received within 12 months, the risk of adrenal insufficiency could last for a further year.

Comparing Different Types of Steroid Administration

To illustrate the difference in immune impact, consider the distinction between localized injections and other forms of steroid administration, such as oral pills or intravenous (IV) treatment.


Feature	Localized Injections (Joint, Epidural)	Systemic Administration (Oral, IV)
Drug Exposure	Primarily local, but with measurable systemic absorption.	Body-wide exposure to the corticosteroid.
Intensity of Immunosuppression	Mild to moderate, depending on dose and individual factors.	More significant and widespread immunosuppression.
Typical Duration of Immune Compromise	1 to 4 weeks for a single injection, potentially longer with higher doses or frequency.	Can persist for weeks after treatment ends, particularly with high doses or prolonged use.
Primary Risk Profile	Low absolute risk of infection, but measurable, especially in older adults; risk of local complications.	Higher risk of systemic infections, adrenal insufficiency, and other side effects due to broad physiological effects.
HPA Axis Effect	Transient suppression is common and can last weeks.	Suppression is a well-known side effect, potentially lasting for extended periods after discontinuation.

How to Reduce Your Risk During Recovery

After a steroid injection, taking proactive measures can help support your immune system and reduce the risk of infection. Recommendations include:

Practice good hygiene: Frequent and thorough handwashing is one of the simplest and most effective preventative measures.
Minimize exposure: Avoid crowded indoor spaces and close contact with individuals who are sick, especially in the first few weeks after the injection.
Healthy lifestyle habits: Focus on getting adequate sleep, eating a balanced diet rich in fruits and vegetables, and managing stress. These practices support overall health and immune function.
Monitor for symptoms: Be aware of any signs of infection, such as fever, cough, or unusual pain, and contact your doctor immediately if they arise.
Inform other providers: If you need further medical or dental treatment within a year, tell your doctor about the steroid injection, as it may affect your adrenal function. Some healthcare providers may also issue a steroid card to keep in your wallet.

Conclusion

While the immunosuppressive effects of a localized steroid injection are typically milder and shorter-lived than those from oral or intravenous steroids, they are a real and important consideration. For most individuals, the immune system is mildly compromised for several weeks post-injection. The exact timeline is influenced by the specific steroid, dosage, and patient factors, making communication with your healthcare provider essential. By being aware of the potential risks and taking sensible precautions, you can minimize the risk of infection and maximize the benefits of your treatment. For more detailed information on steroid effects and specific side effects, consult with your medical provider or a reputable health information source, such as the UpToDate resource on glucocorticoid effects on the immune system.

Frequently Asked Questions

A single, localized cortisone or steroid shot typically causes only a mild and temporary immune compromise. The body's defenses may be slightly lowered for a few weeks, but the risk of severe systemic infection remains low, particularly in healthy individuals.

The immunosuppressive effects of a steroid injection begin quite quickly. Suppression of immune cells and messenger cytokines can occur within hours to days following the injection.

Yes, different steroid formulations and types can have varying effects. Longer-acting agents, such as triamcinolone and methylprednisolone, may suppress cortisol production for a longer duration than more soluble agents like dexamethasone.

You should discuss the timing of any vaccinations with your doctor. Some live vaccines, like the nasal flu spray, are not recommended during the period of immune compromise. Other, non-live vaccines are often safe.

To minimize the risk of infection, you should practice good hand hygiene, avoid crowded indoor spaces, eat a healthy diet, get sufficient sleep, and limit alcohol and sugar intake, especially for the first few weeks.

The absolute risk of a serious infection after a local injection is low but measurable. Studies show a slight increase in the rate of common infections like UTIs and pneumonia, particularly in individuals over 65.

Your healthcare provider may advise you to carry a steroid card. For a single injection, the risk of adrenal insufficiency is typically a concern for up to a month. After multiple injections over a year, this risk may last for a further year.