How Long Does a Cortisone Injection Last? Duration, Efficacy & Limits
Published on 2026-05-12
📋 Key Takeaways
- The effect of cortisone usually begins within 24 to 72 hours, peaking between day 3 and day 7.
- Relief from a cortisone injection lasts from a few weeks to several months depending on the condition.
- Duration varies with the injected site, the dose and individual response.
- Cortisone injections are usually limited to 3 per year at the same site.
- Dr Sébastien Bolduc assesses your condition during a consultation in Saint-Hubert to determine whether an injection is appropriate.
Duration of Action of Cortisone: What the Studies Say
Cortisone injection (corticosteroids) is one of the most prescribed treatments for inflammatory musculoskeletal conditions. But one question keeps coming up: how long does its effect last? The answer depends on several factors that we detail here.
Onset of Action
Cortisone does not work instantly. Allow:
- 24 to 72 hours to feel the first effects
- 3 to 7 days for maximum relief
- Sometimes an initial inflammatory flare-up ("flare reaction") within the first 24 hours
Duration of Relief
The duration of effectiveness varies depending on the pathology being treated and the type of corticosteroid used:
- Bursitis: 4 to 12 weeks, sometimes definitive relief
- Tendinopathies: 2 to 6 weeks (often used as a "therapeutic window" to begin rehabilitation)
- Knee osteoarthritis: 4 to 8 weeks
- Adhesive capsulitis (frozen shoulder): several months
- Carpal tunnel syndrome: 1 to 6 months depending on severity
Long-acting corticosteroids (such as triamcinolone acetonide) offer a longer duration of action than fast-acting corticosteroids (such as betamethasone).
How Many Injections Per Year?
The general rule is not to exceed 3 to 4 injections per year per site. This limitation aims to avoid:
- Weakening of tendons (risk of rupture)
- Skin atrophy and local depigmentation
- Cartilage damage (corticosteroid arthropathy)
- Systemic effects (hyperglycemia, adrenal suppression, immune suppression)
It is essential to use cortisone injections judiciously, as a tool to calm acute inflammation and create a therapeutic window for rehabilitation, rather than as a recurring long-term solution.
Looking for a clinic treatment? Dr. Sébastien Bolduc offers cortisone injection clinic in Saint-Hubert, on Montreal's South Shore. Book an appointment for a personalized assessment.
Frequently Asked Questions
Does the cortisone injection work immediately?
No, it generally takes 24 to 72 hours to feel noticeable improvement. Peak effectiveness is reached around day 5 to day 7. A mild inflammatory flare may occur within the first 24 hours.
Can I get another cortisone injection if the pain returns?
Yes, but not exceeding 3 to 4 injections per year at the same site. A minimum interval of 3 months between two injections is recommended to limit risks.
Why does my pain return after a few weeks?
Cortisone treats inflammation but not the underlying cause (muscle weakness, biomechanical imbalance, overuse). This is why physiotherapy is essential as a complement for lasting results.
Are there long-term side effects?
Repeated injections can weaken tendons, atrophy local subcutaneous fat, or accelerate cartilage degradation. Respecting intervals and the maximum number of injections is therefore crucial.
Does ultrasound-guided injection improve the duration of action?
Yes, because the medication is deposited exactly at the pathological site, which optimizes efficacy and can prolong the duration of relief compared to a less precise blind injection.
Our in-clinic treatments
All treatments are performed under ultrasound guidance by Dr. Sébastien Bolduc in Saint-Hubert.
Questions about your treatment?
Book an appointment with Dr. Bolduc today.
8131 boul. Cousineau, Bureau 203, Saint-Hubert, QC J3Z 0G6