PRP vs cortisone shots for joint pain: which injection, when

If you walk into an orthopedic office with a painful knee, shoulder, or elbow, the conversation often narrows to two syringes: a cortisone shot or a course of PRP injections. They are routinely presented as interchangeable options on a menu, which is misleading. The two injections work through opposite mechanisms, on opposite timelines, at very different prices, and the right choice depends far more on your situation than on which one is better in the abstract.

What each injection actually does

Cortisone is a corticosteroid, a synthetic version of the hormones your body uses to shut down inflammation. Injected into a joint or around a tendon, it suppresses the local inflammatory response quickly and powerfully. Relief often arrives within days and can be dramatic, which is exactly why cortisone has been the workhorse of joint care for decades. What cortisone does not do is heal anything. It silences the alarm without repairing what set it off, and the relief typically fades over weeks to a few months as the underlying problem reasserts itself.

PRP runs in the other direction. Instead of suppressing inflammation, platelet-rich plasma delivers a concentrated dose of your own growth factors to the injured tissue, aiming to shift the local environment toward repair. That process is slow biology: benefit usually builds over weeks to a couple of months rather than days, and it often follows a short series of injections rather than a single shot. The payoff, when it works, is relief that tends to last longer because something in the tissue has actually changed.

What the head-to-head trials show

Tennis elbow offers the cleanest comparison, because researchers have run direct trials of one against the other. In a double-blind randomized trial of chronic lateral epicondylitis, patients who received cortisone did better in the first weeks, but the advantage flipped over time: at one and two years the PRP group had less pain and better function, while the cortisone group had largely regressed (PubMed). That crossover pattern, cortisone winning the sprint and PRP winning the year, shows up repeatedly in the tendon literature.

Knees tell a cautionary story about repetition. A two-year randomized trial published in JAMA gave patients with knee osteoarthritis a corticosteroid injection every three months and found no long-term pain advantage over saline, but measurably greater cartilage loss in the steroid group (PubMed). One cortisone shot is not dangerous, and clinicians still use them thoughtfully, but the evidence has pushed the field away from treating cortisone as a maintenance plan for an arthritic joint. This is also why careful providers cap how many cortisone injections a joint receives per year, a limit reflected in mainstream guidance on the shots (Mayo Clinic). PRP trials in mild to moderate knee arthritis, by contrast, generally show relief that builds more slowly but holds for many months, without evidence of harming cartilage.

The trade-offs nobody puts on the menu

Speed is the first trade-off. If your problem is an acute flare, a wedding next week, or pain so severe you cannot start physical therapy, cortisone's fast relief has real value that PRP cannot match. PRP asks you to be patient through weeks of gradual change, and some patients feel temporarily worse before better as the healing response ramps up.

Money is the second. Cortisone is inexpensive and almost always covered by insurance. PRP is almost never covered, and a full course is a significant out-of-pocket expense, the arithmetic we walk through in what PRP costs and how to judge the value. The honest comparison is not one shot versus one shot but the full course of PRP against repeated rounds of cortisone over the same year, including what each does or does not do to the joint along the way.

Safety rounds out the picture. Both injections are low-risk when performed with sterile technique, but the risk profiles differ. Cortisone's concerns accumulate with repetition: cartilage effects, tendon weakening near the injection site, and a temporary blood sugar rise in people with diabetes. PRP, being made from your own blood, avoids those issues; its main costs are soreness, time, and the possibility that it simply does not help enough to justify the price.

A practical way to decide

A reasonable framework looks like this. Choose cortisone when you need fast, short-term relief: an acute flare, a specific event, pain blocking your rehab, or a one-time diagnostic and therapeutic step. Lean toward PRP when the problem is chronic and the goal is durability: a tendon that has ached for months despite rest and physical therapy, or early to moderate arthritis in a patient trying to stay active and postpone bigger interventions. And be skeptical of either syringe in a bone-on-bone joint, where no injection rebuilds what is gone and surgery is the honest conversation.

The two shots are not rivals so much as tools for different moments. Cortisone buys you weeks, cheaply and quickly, at a cost that compounds with repetition. PRP asks for money and patience up front in exchange for a longer, more biological result. A provider who asks about your timeline, your goals, and your joint's actual condition before reaching for either one is the provider to keep.

Related reading: PRP for knees, joints, and arthritis.