The core difference
One suppresses, one stimulates
Of the two injections, one suppresses and one stimulates: corticosteroid is a potent anti-inflammatory. It reduces the inflammatory response in a joint or around a tendon quickly and reliably. It is not repairing anything — it is turning down a signal.
PRP does close to the opposite. It concentrates the growth factors in your own platelets and delivers them into the tissue, deliberately provoking a healing response. That is why PRP hurts more for a few days afterwards, and why the benefit builds over weeks rather than arriving immediately. The mechanism is covered in full on our PRP therapy page.
Get an examination before an injectionThe evidence
What the head-to-head trials show
The head-to-head trials show cortisone ahead in the short term and PRP ahead in the long term, most clearly in tennis elbow (lateral epicondylitis), where the comparison has been studied most directly and the picture is unusually clear once you separate short-term from long-term.
A systematic review and meta-analysis of randomized controlled trials of 11 trials in 730 patients found corticosteroid better for function in the first two months and PRP better for pain and function from six months on (the short-term pain advantage for corticosteroid did not survive sensitivity analysis), while a pairwise and network meta-analysis of 20 randomized trials in 1,271 patients ranked corticosteroid first for VAS pain and most function scores in the short term and PRP first for VAS and DASH scores in the long term.
On safety, a 2026 systematic review and meta-analysis of randomized trials of 10 tennis-elbow trials found complication rates for PRP comparable to those of corticosteroid and saline injections, with no serious adverse events reported. Injection-site pain was more common after PRP (13% versus 7%), and it resolved in every study.
In the knee, the 42-trial, 3,696-patient pooled analysis found PRP beating corticosteroid on WOMAC pain by a mean difference of −8.06 (95% CI −13.62 to −2.51, p = 0.004) and on VAS by −1.11 (95% CI −1.64 to −0.59, p ≤ 0.0001), with the gap widest around six months. We go through the knee evidence in detail in Does PRP work for knee arthritis?. Across the head-to-head trials, cortisone wins early and PRP wins later.
Head to head
How they compare
Here is how they compare: cortisone suppresses inflammation and works within days, while PRP stimulates a repair response that builds over weeks.
| Cortisone | PRP | |
|---|---|---|
| What it does | Suppresses inflammation | Stimulates a repair response |
| Onset | Days | Weeks |
| Short term (under 2 months) | Ranked first for pain and function in tennis elbow | Behind corticosteroid over this window |
| Long term (6 months plus) | Falls behind | Ranked first for pain and function |
| Discomfort after | Usually minimal | Several days of increased ache is normal |
| Repeat use | Limited — repeated knee injections were linked to greater cartilage loss in a 2-year trial | No equivalent cartilage-loss signal in trials |
| Complication rate | Comparable to PRP and saline in RCT review | Comparable overall; more injection-site pain; no serious adverse events |
| Anti-doping | Restricted in competition | Permitted |
Cortisone
When a steroid injection is the right answer
A steroid injection is the right answer when you need fast relief from an acute problem, as in these situations:
- An acutely inflamed joint where you need function back within days
- A flare that needs settling so you can actually do physical therapy
- A first injection for a problem you have not treated before
- Any case where the horizon that matters to you is the next six weeks, not the next six months
There is nothing wrong with cortisone. The problem is not the drug — it is using it repeatedly as a long-term strategy for a chronic problem, which is precisely the pattern the long-term trial data argues against.
PRP
When platelet-rich plasma is the better fit
Platelet-rich plasma is the better fit for chronic problems where a durable result matters more than speed, including:
- Chronic tennis elbow — where PRP ranks first for pain and function beyond six months
- Mild-to-moderate knee osteoarthritis, where PRP beat corticosteroid on WOMAC pain by −8.06 in pooled trial data
- Anyone who has already had two or three steroid injections into the same structure
- Athletes subject to anti-doping rules, since PRP is autologous and permitted
- Plantar fasciitis that has persisted for months, where a 2025 meta-analysis of 24 trials in 1,653 patients found better pain relief with PRP than corticosteroid at three to six months, though not at one month or one year
- Cases where you can invest six months for a durable result rather than needing relief this week
The joint-by-joint detail (knee, shoulder, hip, elbow, Achilles) is on our PRP for joint, tendon and cartilage restoration page. In short, PRP is the better fit when the problem is chronic and you can wait for the benefit to build.
The tradeoff nobody mentions
Why repeat cortisone becomes a problem
Repeat cortisone becomes a problem because repeated corticosteroid injections can damage the tissue they are meant to protect. In a two-year randomized trial in 140 people with knee osteoarthritis, triamcinolone injected every 12 weeks caused more cartilage loss than saline and gave no better pain relief. For an acute flare that is an acceptable trade. For a problem you have had for three years and injected four times, it is worth asking whether you are managing the pain while quietly making the tissue worse.
This is a common reason patients ask Protocol Health about PRP. Not because they read about it — because they have run out of steroid injections they are comfortable having.
It is also worth knowing that PRP is not a single-shot treatment the way a steroid injection often is. A 2025 review in the Journal of Clinical Medicine cites a study in which triple injections outperformed single injections over 12 months, and notes that most trials used two- or three-injection series. Compare courses, not shots.
Where the problem is genuinely structural, PRP is not the only option either. Shockwave therapy and peptides for soft-tissue recovery both sit in our pain and injury recovery program and are sometimes the better call.
Choosing
The questions that actually decide it
The questions that decide it are about timeframe, injection history, diagnosis and severity:
Work through these before you choose
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The fourth question matters more than the choice of injection. Lateral hip pain is often gluteal tendinopathy rather than hip arthritis; knee pain sometimes originates at the hip or back. An injection into the wrong structure fails regardless of what is in the syringe — which is why every PRP plan at Protocol Health starts with an examination by a board-certified physiatrist. You can see how that works on our how it works page, or read Dr. Dentico's background on our team page.
PRP vs cortisone comes down to timeframe. Cortisone gives faster relief that fades over weeks to months; PRP builds over weeks and, in tennis elbow and knee osteoarthritis trials, holds up better at six months and beyond. Use cortisone for an acute flare, consider PRP for a chronic problem or after repeated steroid shots, and let an examination decide which structure gets injected.
FAQ
Frequently Asked Questions
Can I have PRP if I have already had cortisone?
Yes. Many PRP patients have had steroid injections previously. There is usually a recommended interval between the two, which depends on how recently you were injected.
Is PRP just a stronger cortisone shot?
No — they work by opposite mechanisms. Cortisone suppresses inflammation for faster short-term relief. PRP provokes a repair response with slower onset. They suit different problems.
Which one works better for tennis elbow?
It depends on the timeframe. In pooled tennis-elbow trials, corticosteroid did better in the first two months and PRP did better from six months on, so PRP suits chronic cases that have not responded to rest, bracing and therapy. A 2026 review of randomized trials found PRP complication rates comparable to corticosteroid and saline, with more injection-site pain after PRP.
How long does a cortisone injection take to work and how long does it last?
Cortisone usually starts easing pain within a few days, which is why it suits acute flares. Relief often fades over weeks to a few months, and in tennis elbow trials its advantage over PRP was limited to roughly the first two months. Duration varies by joint, diagnosis and dose.
Do I have to stop anti-inflammatories?
For PRP, usually yes, for a window before and after treatment — NSAIDs may blunt the inflammatory signaling the treatment depends on. You will be given specific timing.
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Related at Protocol Health
Get an examination before an injectionThis article is educational and is not medical advice. It does not diagnose, prevent, treat or cure any condition. Talk with a licensed clinician about your own situation.