How Long Does a Cortisone Shot Take to Work?

Quick Answer

A cortisone shot (corticosteroid injection) typically takes 2–7 days to reach full effectiveness. Some patients feel significant relief within 24–48 hours, while others may need up to 2 weeks. The injection usually provides pain relief lasting 6 weeks to 3 months, though results vary by condition and injection site.

Timeline by Injection Site

How quickly a cortisone shot works and how long it lasts depends heavily on where it is injected:

Injection Site	Onset of Relief	Typical Duration of Relief
Knee	2–5 days	6 weeks–3 months
Shoulder	3–7 days	4–6 weeks
Hip	2–5 days	6 weeks–3 months
Elbow (tennis elbow)	2–4 days	4–8 weeks
Wrist/hand	2–5 days	4–6 weeks
Foot (plantar fasciitis)	2–7 days	4 weeks–3 months
Spine (epidural)	3–7 days	2 weeks–3 months

Joints with more blood flow tend to respond faster, while areas with less vascularity like tendons may take longer.

What to Expect After the Injection

Understanding the normal post-injection experience helps set realistic expectations:

• First few hours: The local anesthetic mixed with the cortisone provides immediate but temporary numbness and relief
• Hours 6–24: A "cortisone flare" may occur as the anesthetic wears off, causing temporary increased pain and swelling at the injection site (affects roughly 10–20% of patients)
• Days 1–3: Gradual onset of anti-inflammatory effects
• Days 3–7: Most patients experience significant improvement
• Days 7–14: Full effect is typically reached

The Cortisone Flare

A cortisone flare is a temporary worsening of pain that occurs within the first 24–48 hours after injection. It happens because cortisone crystals can irritate the joint lining before they dissolve. To manage a flare:

• Apply ice to the injection site for 15–20 minutes at a time
• Take over-the-counter pain relievers like acetaminophen
• Rest the affected area
• The flare typically resolves within 1–3 days

How Long Does Relief Last?

The duration of pain relief varies significantly based on several factors:

• Condition being treated: Osteoarthritis injections may last 4–6 weeks, while bursitis injections can provide relief for 3–6 months
• Severity of inflammation: More severely inflamed joints may not respond as long
• Number of previous injections: Effectiveness can decrease with repeated injections in the same area
• Activity level: High-impact activities on the treated joint may shorten the benefit window

Side Effects and Risks

Cortisone injections are generally safe, but potential side effects include:

• Temporary pain and swelling at the injection site
• Skin lightening or thinning near the injection site
• Temporary blood sugar elevation (important for diabetics to monitor)
• Tendon weakening with repeated injections
• Cartilage damage with excessive use in weight-bearing joints
• Rare infection at the injection site (less than 1% risk)

Practical Tips for Best Results

• Rest the area for 24–48 hours after the injection to allow the medication to take effect
• Avoid strenuous activity for at least 2–3 days post-injection
• Apply ice if you experience a cortisone flare
• Follow up with physical therapy to address the underlying cause of pain
• Keep a symptom diary to help your doctor evaluate effectiveness
• Limit injections to no more than 3–4 per year in the same joint to reduce the risk of cartilage damage

When Cortisone Shots May Not Be the Right Choice

Cortisone injections are not recommended for active joint infections, uncontrolled diabetes, or areas where tendons are already weakened. Patients on blood thinners should discuss risks with their doctor. If two consecutive injections provide minimal relief, alternative treatments such as hyaluronic acid injections, platelet-rich plasma therapy, or surgical options may be more appropriate.