Written and medically reviewed by David Nazarian, MD — Board Certified in Internal Medicine and Medical Director of PRP Treatment Beverly Hills. Last medically reviewed: October 2026.
Quick answer: Both platelet-rich plasma (PRP) and hyaluronic acid (HA) injections are used in nonsurgical management of knee osteoarthritis. Recent randomized-trial meta-analyses generally report greater average improvement in pain and function with PRP than HA at medium-term follow-up, but results vary by PRP preparation, osteoarthritis severity, number of injections, and study quality.
What is hyaluronic acid?
Hyaluronic acid is a naturally occurring component of synovial fluid. Injectable HA products are used as viscosupplementation with the goal of improving joint lubrication and symptoms. Products differ in molecular weight, formulation, and injection schedule.
How is PRP different?
PRP is prepared from the patient’s own blood and contains concentrated platelets and associated signaling proteins. It does not work as a lubricant. Its proposed effects involve modulation of local inflammatory and cellular signaling, although the exact clinical mechanism remains uncertain.
What do recent studies show?
Several recent systematic reviews of randomized controlled trials have found better average WOMAC and pain outcomes with PRP compared with HA, especially at 6 to 12 months. A 2025 systematic review including 42 randomized trials favored PRP over HA for several pain and function outcomes, while a 2026 network meta-analysis found both leukocyte-rich and leukocyte-poor PRP superior to placebo for function at 6 to 12 months. These are group averages and do not guarantee an individual response.
Is one always better?
No. Patient age, osteoarthritis severity, inflammatory pattern, previous injections, expectations, cost, contraindications, and clinician experience all matter. Guidelines also differ in how strongly they recommend or discourage various injection options.
What about combining PRP and HA?
Combination therapy has also been studied. A 2024 meta-analysis reported better outcomes for PRP plus HA compared with HA alone, but no clear superiority over PRP alone. That does not establish combination therapy as necessary or standard for every patient.
My approach
I first confirm that knee osteoarthritis is actually the main pain generator and review disease severity, prior treatment, function, imaging, rehabilitation, and expectations. The decision between PRP, HA, corticosteroid, or another approach should come after that evaluation.
Related: PRP knee injections, PRP vs cortisone, and how I decide whether PRP is worth doing.
