There is no single “best” injection for osteoarthritis. The right choice depends on your joint, the severity of your cartilage loss, how long you need relief, and what your insurance covers. Corticosteroid injections remain the most widely recommended option for quick pain relief, earning a strong recommendation from the American College of Rheumatology for knee osteoarthritis. But they’re a short-term fix. For longer-lasting results, hyaluronic acid and platelet-rich plasma each have meaningful evidence behind them, with tradeoffs in cost, coverage, and how long the benefits hold.
Here’s what the evidence actually shows for each option, so you can have a more informed conversation with your doctor.
Corticosteroid Injections: Fast but Temporary
Corticosteroid (cortisone) injections are the most commonly used and most studied injection for osteoarthritis. They work by reducing inflammation inside the joint, which is what drives much of the pain and swelling. Most people notice improvement within a week, and relief typically lasts several weeks to a few months.
The main limitation is durability. The effect wears off, and most providers cap treatment at three or four injections per year in the same joint. There’s a good reason for that limit: research on cartilage health shows that at low cumulative doses, corticosteroids can actually support cartilage recovery. But once you exceed certain thresholds, the relationship flips. Higher cumulative doses are associated with cartilage damage and loss of the proteins that keep cartilage healthy. In animal studies, visible cartilage changes became significant only after eight or more injections at high doses, but the concern is real enough that repeated use over years raises questions about whether you’re trading short-term relief for faster joint deterioration.
For someone with moderate pain who needs relief now, a corticosteroid injection is often the logical first step. It’s affordable, widely covered by insurance, and reliably effective in the short term. But it’s not a strategy you want to lean on indefinitely.
Hyaluronic Acid: A Slower, Longer Approach
Hyaluronic acid injections, sometimes called viscosupplementation, take a different approach. Instead of fighting inflammation, they replace a substance your joint naturally produces. Healthy joints contain hyaluronic acid in the synovial fluid, where it acts as both a lubricant and a shock absorber. In osteoarthritis, that fluid thins out and loses its protective qualities. Injecting a synthetic or purified version aims to restore some of that cushioning.
The relief isn’t instant. It typically takes a series of three to five weekly injections (or a single injection with newer formulations) before you notice improvement, and the full benefit may not peak for several weeks after the series is complete. When it works, though, the effects can last six months or longer.
Hyaluronic acid is FDA-approved specifically for knee osteoarthritis, and Medicare covers it under specific conditions: you need a confirmed radiological diagnosis, documented failure to improve after at least three months of conservative treatment (pain relievers, exercise, physical therapy, weight loss if relevant), and at least six months between injection series. If you’ve had a previous round, your medical records need to show it actually helped. Insurance coverage for joints other than the knee is less consistent. Interestingly, a pilot study comparing hyaluronic acid in hips versus knees found that hip injections produced improvements across more outcome measures, including stiffness and physical function, not just pain. But the knee remains the joint with the strongest coverage and the most data.
Platelet-Rich Plasma: Stronger Long-Term Results
Platelet-rich plasma (PRP) is made from your own blood. A sample is drawn, spun in a centrifuge to concentrate the platelets and growth factors, then injected into the joint. The idea is that these concentrated growth factors can reduce inflammation, stimulate some degree of tissue repair, and shift the joint environment in a healthier direction.
A meta-analysis published in Pain Medicine compared PRP head-to-head with hyaluronic acid in knee osteoarthritis patients. At six months, PRP produced significantly greater pain reduction. At twelve months, the gap widened further, with PRP patients reporting meaningfully better pain scores and functional improvement. The functional benefits showed up as early as three months and held through the full year of follow-up.
The catch is practical. PRP is not FDA-approved as a drug (it’s considered an autologous blood product), and most insurance plans, including Medicare, don’t cover it. Out-of-pocket costs typically range from $500 to $2,000 per injection depending on your location and provider. There’s also no standardized preparation method, which means the concentration of platelets can vary between clinics. That inconsistency makes it harder to predict exactly what you’ll get.
For people with mild to moderate osteoarthritis who can afford the out-of-pocket cost, PRP offers the most compelling evidence for sustained improvement. It’s less clearly beneficial in severe, bone-on-bone cases.
Bone Marrow Concentrate: Promising but Early
Bone marrow aspirate concentrate (BMAC) goes a step further than PRP. It’s harvested from your own bone marrow (usually the back of the pelvis), processed to concentrate stem cells and growth factors, and injected into the joint. The goal is not just symptom relief but some degree of biological repair.
A study published in Scientific Reports followed 37 knees with advanced osteoarthritis (the kind where joint replacement is typically discussed) for four years after BMAC injection. The average symptom score dropped from 40 to 18 on the WOMAC scale, a widely used measure of pain, stiffness, and function. Thirty-five of the 37 knees showed improvement from the first follow-up through the final one. Multiple randomized controlled trials since 2013 have confirmed safety and shown functional improvement compared to hyaluronic acid or PRP.
The downsides mirror PRP but are amplified. It’s more invasive (requiring bone marrow extraction), more expensive (often $3,000 to $8,000), and not covered by insurance. The evidence base is growing but still small compared to corticosteroids or hyaluronic acid. This is an option worth knowing about, particularly if you have advanced disease and want to delay joint replacement, but it’s not yet a mainstream first-line treatment.
How Your Joint and Disease Stage Matter
Not every injection works equally well in every situation. Corticosteroid injections are effective across joints and severity levels for short-term flares. Hyaluronic acid has the strongest evidence in the knee and is only FDA-approved and reliably covered for knee osteoarthritis, though off-label use in the hip and shoulder is common. PRP appears most effective in mild to moderate disease, where there’s still cartilage present that can respond to the biological signals. BMAC has shown results even in advanced cases, but the evidence is limited.
The accuracy of the injection itself also matters more than many people realize. A systematic review of 13 studies found that ultrasound-guided knee injections hit the joint space 95.4% of the time, compared to 82% for traditional landmark-guided (blind) injections. If you’re paying out of pocket for PRP or BMAC, asking for ultrasound guidance is worth it. Even for covered injections, better accuracy translates to better results.
Comparing Your Options at a Glance
- Corticosteroids: Fastest relief (within a week), lasts weeks to months, covered by insurance, limited to 3-4 per year, potential for cartilage harm with repeated high-dose use.
- Hyaluronic acid: Slower onset (weeks), lasts up to 6 months, covered by Medicare for knee OA after conservative treatment fails, requires repeat series no sooner than every 6 months.
- PRP: Moderate onset, pain and function benefits lasting 6-12 months that outperform hyaluronic acid in studies, rarely covered by insurance, costs $500-$2,000 per injection.
- BMAC: Most biologically ambitious option, 4-year follow-up data showing sustained improvement even in advanced disease, not covered by insurance, costs $3,000-$8,000.
Choosing Based on Your Situation
If you need quick relief from a painful flare and want something covered by insurance, a corticosteroid injection is the proven starting point. If you’re looking for longer-lasting relief and have knee osteoarthritis that hasn’t responded to simpler treatments, hyaluronic acid is the next step with established insurance pathways. If you can invest out of pocket and want the best available evidence for sustained pain reduction and functional improvement over a year, PRP has the strongest comparative data. And if you have advanced disease, want to delay surgery, and can manage the cost, BMAC is worth discussing with an orthopedic specialist who has experience with the procedure.
No injection reverses osteoarthritis or regrows cartilage to its original state. All of these are tools for managing symptoms, improving function, and buying time. The best injection is the one that matches where you are in the disease, what your joint needs right now, and what you can realistically access.