How long after an infiltration does the pain disappear?

Have you just had an injection and are wondering how long it will take before you start feeling better? It’s the question everyone asks after this type of treatment, and honestly, the answer deserves serious consideration. Because no, it’s not instant—and yes, it depends on a lot of factors!

In this article, I’ll explain everything you need to know about how long it takes to feel relief, the different types of injections, and what you can actually expect after the procedure. Hang in there—let’s figure this all out together. 💡

To remember: After a corticosteroid injection, pain relief usually occurs within 24 hours a day, 7 days a week. With viscosupplementation, it usually takes 2 to 6 weeks to feel the first effects.

What exactly is an infiltration?

An injection is the direct administration of a therapeutic agent into a joint, tendon, or painful tissue. The goal? To act locally to reduce inflammation and relieve pain—much more effectively than a simple oral anti-inflammatory medication.

There are several types of injectable products, and that's where it gets interesting—because each one has its own onset time!

Corticosteroids (cortisone)

Cortisone remains the most commonly used medication. It acts as a powerful local anti-inflammatory. Rheumatologists, sports medicine doctors, and orthopedists use it to treat osteoarthritis of the knee and hip, tendinitis, bursitis, and lower back pain.

Viscosupplementation (hyaluronic acid)

In this procedure, hyaluronic acid is injected directly into the joint—usually the knee. It is not an anti-inflammatory; rather, it lubricates the joint and gradually restores the cartilage. The effect is therefore slower to take hold, but often longer-lasting.

Local anesthetic (Xylocaine)

Sometimes used in combination with corticosteroids to provide immediate relief, local anesthetics take effect within a few minutes but last only a few hours. They have no long-term therapeutic effect.

How long does it take to feel relief, depending on the type of injection?

It really is the central question, and the results vary depending on the product injected and the area treated. Here's a summary table to give you a clear picture!

The time frame based on the joint area

The time it takes to feel relief also varies depending on the targeted area. For the knee and the shoulder, the effects of corticosteroids are often felt within 48 to 72 hours. For lumbar injections (back, sciatica), it can sometimes take 5 to 7 days to feel a real improvement.

For the hip, the recovery time is often similar to that for the knee—between 2 and 5 days—but may vary depending on the severity of osteoarthritis and the condition of the cartilage. If you are experiencing pain related to a algodystrophy of the knee, this joint may require a more gradual approach.

Why might the pain get worse right after the injection?

Ah, that moment! It often comes as a surprise to many patients: within the first 24 to 48 hours after the injection, it’s quite possible to feel a temporary flare-up of pain. It's no big deal, don't worry!

This phenomenon is called a «post-injection flare.» It’s caused by a mild local inflammatory reaction triggered by the medication itself. It usually goes away within 48 hours and often signals the start of relief. It’s a sign that your body is responding!

✅ Good to know: «Post-injection flare» affects approximately 2 to 10 % of patients following a corticosteroid injection. It resolves on its own within 24 to 48 hours. Simply applying ice to the area is usually enough to relieve the discomfort.

How long does the relief last after an injection?

That really varies! For a cortisone injection, the pain-relieving effects last, on average, between 3 weeks and 3 months, sometimes up to 6 months, depending on the individual case and the condition of the joint.

With viscosupplementation, the results are often longer-lasting: on average, between 6 months and 1 year, with some patients reporting that their joint comfort lasts up to 18 months.

Why does the pain return after an injection?

That’s a question everyone asks! An injection doesn’t cure the underlying cause of the problem—it relieves the symptoms. If osteoarthritis, tendinitis, or bursitis progresses, the pain may return once the medication’s effects wear off.

That is why it is often recommended to combine injections with physical therapy, rehabilitation, or tailored exercises to strengthen the muscles around the joint and prevent relapses. For certain conditions such as cruralgia, a multidisciplinary approach is particularly important.

Rest after an injection: Is it really necessary?

Spoiler: Yes, and it's non-negotiable if you want the best results! After an injection, 48 hours of relative rest are recommended. Under no circumstances should you resume sports or put intense strain on the treated joint during this period.

• Avoid strenuous physical activity and contact sports for at least 48 hours.
• Apply ice to the area if it feels hot or painful (10 to 15 minutes, 2 to 3 times a day).
• Walking slowly is generally still possible, unless your doctor advises otherwise.
• Gradually resume your normal activities starting on the third day.

For injections in the lower back or hip, it’s often possible to return to a seated work position as early as the next day. For areas that are under greater strain, such as the shoulder or knee, exercise a little more caution.

What side effects should I be aware of?

Injections are generally very well tolerated, but there are a few side effects—so you should be aware of them!

Side Effects of Corticosteroids

Cortisone can cause a slight increase in blood sugar levels, particularly in people with diabetes. Monitoring blood sugar levels is therefore recommended in the days following the injection. Other possible side effects include localized skin atrophy or depigmentation at the injection site—rare but possible.

The Risk of Infection

Very rare (fewer than 1 in 30,000 cases, according to the medical literature), but it does happen. If you experience intense redness, abnormal warmth, or a fever within 48 hours of the injection, you should contact your doctor right away. This isn’t meant to scare you—it’s just to make sure you stay extra vigilant!

How many infiltration tests can be performed per year?

This is one of the most frequently asked questions! The general rule, recommended by the French Society of Rheumatology, is to Do not exceed 3 corticosteroid injections per year at the same joint site, with a minimum interval of 6 weeks between each injection.

Too frequent injections could eventually weaken the cartilage and periarticular tissues—the opposite of what we’re trying to achieve. Viscosupplementation, on the other hand, can be administered as an annual treatment, often consisting of 1 to 3 injections spaced one week apart. Chronic pain, such as that seen after a cracked rib, may require a specific treatment strategy involving multiple injections.

What are the contraindications for injections?

Not everyone is a candidate for an injection. The main contraindications are:

Active local or systemic infection — That’s an absolute contraindication. Under no circumstances should cortisone be injected if an infection is present, as it could make the infection worse.

Poorly controlled diabetes — Cortisone can significantly disrupt blood sugar levels. It is essential to discuss this with your doctor beforehand.

Anticoagulant therapy — The risk of local bleeding is increased. Treatment adjustments may be necessary before the procedure.

Pregnancy is also a relative contraindication, to be evaluated on a case-by-case basis with the rheumatologist or the physician performing the procedure.

Viscosupplementation or cortisone: Which injection should you choose?

The decision is always up to the doctor, but here are the basics to help you understand the difference!

Visit cortisone is ideal when pain is severe and you need quick relief—it’s the perfect ally for acute inflammatory flare-ups. The viscosupplementation, on the other hand, is generally recommended for moderate to severe osteoarthritis of the knee or hip, when the goal is to achieve a long-lasting effect and improve cartilage quality.

Good news regarding reimbursement: viscosupplementation of the knee is partially covered by France’s national health insurance, under certain conditions. For other joints, coverage remains limited—check with your supplemental health insurance provider. 👍

What You Really Need to Know About Post-Infiltration Timeframes

To put it simply: if you’ve had a cortisone injection, you can expect relief within 24 hours to 7 days, with effects that can last from several weeks to several months. If you’ve had viscosupplementation, be patient—the benefits take longer to kick in but last longer!

In any case, Follow the recommended rest period, watch for any unusual reactions, and don’t hesitate to contact your doctor again if the pain doesn’t subside after 10 to 15 days. Injections are a powerful therapeutic tool, but they are always part of a comprehensive treatment plan—including physical therapy, adapted physical activity, and a healthy lifestyle—to ensure truly lasting results!