Which injection works faster: PRP or cortisone?

Cortisone works faster, usually within 2–5 days, while PRP takes 2–4 weeks to begin relieving pain.

How long do cortisone and PRP injections last?

Cortisone injections typically last 3–8 weeks, while PRP injections may provide relief for 6–12 months in early to moderate osteoarthritis.

Do PRP or cortisone injections rebuild cartilage?

No. Neither injection rebuilds cartilage. PRP may help slow cartilage breakdown, but cortisone can weaken cartilage with repeated use.

What are the side effects of PRP vs cortisone injections?

Cortisone may cause short-term pain flare, skin thinning, or elevated blood sugar. PRP is made from your own blood and has minimal side effects, typically mild soreness at the injection site.

How often can I have cortisone or PRP injections?

Cortisone is usually limited to 3–4 injections per year per joint. PRP can be repeated 1–3 times a year based on your response.

Is PRP better for early-stage osteoarthritis?

Yes, PRP is more effective in early to moderate stages of osteoarthritis, whereas cortisone is best for short-term symptom control or flare-ups.

Can I have PRP and cortisone injections together?

It’s not recommended to have them too close together. Cortisone may reduce PRP’s effectiveness, so spacing them apart is important.

Which injection is more affordable: PRP or cortisone?

Cortisone is more affordable and often covered by the NHS. PRP is a private treatment and costs more due to processing and equipment.

Where can I get PRP or cortisone injections for knee osteoarthritis?

You can get ultrasound-guided PRP or cortisone injections at ACTIVATE Musculoskeletal Clinic locations in Kensington, Maidstone, Kings Hill, and Harley Street. Booking is available online.

Which is better overall: PRP or cortisone for knee osteoarthritis?

PRP is better for long-term symptom relief in early-stage arthritis. Cortisone is ideal for quick, short-term pain relief. The best option depends on your arthritis stage and goals.

PRP vs Cortisone Injections for Knee Osteoarthritis

Q: What is a cortisone injection and how does it work?

Cortisone is a synthetic anti-inflammatory injection used to reduce inflammation and pain in the knee joint. It works quickly, often within 2–5 days, and is commonly used to manage osteoarthritis flare-ups.

Q: What is PRP and how does it work?

PRP (platelet-rich plasma) is derived from your own blood and injected into the knee to reduce inflammation and support joint health. It may help slow cartilage wear and relieve symptoms gradually over a few weeks.

Mustafa Alnaib
Aug 29
4 min read

If you're struggling with knee pain from osteoarthritis, you’ve likely come across PRP (platelet-rich plasma) and cortisone injections as non-surgical options. But how do they compare? Which one lasts longer, works better, or suits your stage of arthritis? This article answers all your questions with clarity.

❓ What is a cortisone injection and how does it work?

Cortisone is a synthetic anti-inflammatory that helps to calm down joint inflammation in knee osteoarthritis. It works quickly, usually within 2–5 days, making it useful during flare-ups.

📖 Learn more in our dedicated blog:👉 Cortisone Injections for Knee Osteoarthritis – Your Comprehensive FAQ

❓ What is PRP and how does it work?

PRP is obtained from a small sample of your own blood. The sample is spun in a machine to extract the platelets and plasma containing growth factors. The result is a natural healing effect and support for joint tissue health.

📖 Dive deeper in this article:👉 PRP Injections for Knee Osteoarthritis – Could This Be the Relief You’re Looking For?

❓ Which injection works faster?

Treatment	Time to Relief
Cortisone	2–5 days (fast)
PRP	2–4 weeks (gradual)

If you’re in a flare, cortisone may provide faster relief. If you’re looking for longer-term results, PRP may be worth the wait.

❓ How long does the benefit last?

Cortisone: Typically 2–6 weeks, but varies.
PRP: Effects can last 6 to 12 months in early to moderate arthritis.

❓ Do these injections help rebuild cartilage?

Neither option regenerates cartilage.

Cortisone may actually worsen cartilage damage with overuse.
PRP enhances the joint’s biological environment, helping preserve cartilage, slow deterioration, reduce wear, and keep the joint healthier for longer

❓ Which one is safer?

Cortisone risks: Flare-up pain and skin thinning. Cortisone knee injections can temporarily raise blood sugar in diabetic patients.
PRP: Made from your own blood. Very low risk, with only minor soreness at the injection site.

Want a deeper dive?👉 Ultrasound-Guided Injection: What, How, and Why

❓ How many injections can I have?

Cortisone: Up to 2–3 times per year per joint, due to potential cartilage weakening.
PRP is safe, and typically provided as 1–3 injections in a course (4-6 weeks apart), and if it helps, the treatment can be safely repeated every 6–12 months.

❓ Is PRP better for early-stage arthritis?

Yes. PRP is more effective in early to moderate osteoarthritis, where it can calm inflammation and support joint preservation. There is no evidence to support PRP injection in advanced or severe osteoarthritis.

❓ Can I combine PRP and cortisone?

This is not recommended practice. Steroids may blunt the effects of PRP.

Suggested sequence:

Cortisone for urgent flare relief
PRP later for sustained support

Need guidance on timing? Contact us here

❓ What about other options like hyaluronic acid or Arthrosamid?

Other injections may be better suited for you if you've tried PRP/cortisone already.

❓ Which one costs more?

Cortisone: Affordable and often NHS-covered.
PRP: A private treatment, higher in cost due to equipment and processing. Rarely funded by the NHS.

View our prices page here:👉 Prices – Injections & Ultrasound

❓ What if I want both knees treated?

Both cortisone and PRP can be administered to both knees at the same time.

We assess both knees in one visit and treat accordingly

👉 One Appointment – Private Joint Scanning & Injection

❓ How do PRP and cortisone injections for knee arthritis compare overall?

Feature	PRP	Cortisone
Onset of action	Slower (2–4 weeks)	Fast (2–5 days)
Duration of relief	6–12 months	2–6 weeks
Rebuilds cartilage?	No, but may slow wear	No, and may damage over time
Side effects	Minor	Flare, sugar spike, cartilage thinning with repeated use
Suitable for early OA	✅ Yes	✅ For flare control
Suitable for late OA	May be less effective	Short term symptom management
Cost	Higher	Lower

CLICK HERE TO FIND OUT WHICH INJECTION IS THE RIGHT OPTION FOR YOU

❓ Where can I get these injections?

We offer ultrasound-guided PRP and cortisone injections in London and Kent

❓ What happens during the appointment?

We assess your knee clinically and review relevant imaging.
Discuss options and get a recommendation tailored to your arthritis stage.
Injections are carried out on the same day in most cases, under ultrasound guidance if required.

See more:👉 Clinic Services – Doctor-Led Injections & Imaging

📌 Summary

Cortisone and PRP injections both play important roles in managing knee arthritis. Here's the simplified take:

⚡ Need fast relief? Cortisone is the go-to.
🌱 Want longer-lasting, natural help? PRP is worth exploring in mild to moderate knee osteoarthritis.
🤔 Need advice tailored to you? Book a consultation 🔗 Book Now | 💬 Contact Us

📧 Email: alnaib@mskclinic.co.uk

📞 Call us on WhatsApp: +447369222132

About the Author: Dr. Mustafa Alnaib MBChB, MRCS, MSc, FEBOT is an orthopaedic surgeon, musculoskeletal doctor and Clinic Director at ACTIVATE Musculoskeletal Clinic in Kent & London