Platelet-rich plasma, or PRP, has become one of the most talked-about treatments in modern sports medicine, orthopedics, and podiatry. But does it actually work? In this first episode of season 3 we take a detailed look at the science behind PRP—from how it is prepared from a patient's own blood to the growth factors and signaling molecules that may influence tissue healing. We explore how PRP is used in orthopedics and foot and ankle medicine, including treatment of knee arthritis, plantar fasciopathy, Achilles tendinopathy, and other tendon and joint conditions. But this episode isn't simply about why PRP might work. We also examine the evidence showing where PRP doesn't appear to provide a meaningful benefit over placebo. You'll learn why two treatments both labeled "PRP" can actually be very different biologic products, why platelet concentration and white blood cell content matter, and why a convincing biological mechanism doesn't necessarily translate into better outcomes for patients. Most importantly, we look at what randomized clinical trials and meta-analyses actually tell us about PRP—and how patients should think about the potential benefits, limitations, costs, and alternatives before deciding whether it is right for them. PRP isn't magic, but it isn't snake oil either. The truth is considerably more interesting.
Platelet-rich plasma has become a popular treatment in sports medicine, orthopedics, and podiatry. But what exactly is PRP, and how much evidence do we actually have that it works?
In this episode, we break down the science, clinical applications, and controversies surrounding PRP.
PRP is a concentrated preparation of a patient's own blood containing a higher concentration of platelets than normal blood.
Platelets do more than help form blood clots. They contain numerous signaling proteins and growth factors that participate in tissue repair, inflammation, angiogenesis, cellular recruitment, and tissue remodeling.
The process generally involves:
Importantly, PRP is not one standardized product.
Different systems can produce substantially different platelet concentrations and cellular compositions.
Depending on the preparation, PRP can contain:
We discuss why leukocyte-rich and leukocyte-poor PRP may behave differently and why the optimal formulation remains uncertain for many conditions.
Activated platelets release biological mediators that can influence:
But biological plausibility doesn't necessarily equal clinical effectiveness.
One of the major themes of this episode is the difference between mechanistic evidence and patient outcomes.
We discuss the evidence surrounding PRP for:
Knee osteoarthritis
PRP has some of the more encouraging evidence in this area. Several randomized trials demonstrate improvements in pain and function, although the magnitude and durability of benefit remain debated.
Rotator cuff tendinopathy
Evidence is mixed, but some newer studies suggest PRP may provide greater longer-term improvement than corticosteroid injections.
Tennis elbow
Despite a strong biological rationale and widespread clinical use, recent placebo-controlled evidence has not demonstrated a convincing benefit over placebo.
Achilles tendinopathy
This is one of the most important examples discussed in the episode. Despite a compelling biological rationale, recent randomized placebo-controlled studies have failed to demonstrate a meaningful advantage of PRP over placebo.
We examine potential applications for:
The evidence varies considerably between conditions.
Some studies suggest PRP may provide longer-term improvement compared with corticosteroid injections.
However, comparisons against corticosteroid don't answer the same question as comparisons against placebo.
The key question remains:
Does PRP itself provide a clinically meaningful benefit beyond the effects of the injection and rehabilitation?
Despite being one of the most popular applications for PRP, high-quality placebo-controlled evidence has been disappointing.
Recent meta-analyses have found no significant improvement in pain or function compared with placebo.
This illustrates an important lesson:
A treatment can have a highly plausible biological mechanism without producing a meaningful clinical benefit.
Injection studies are particularly susceptible to placebo effects.
Patients receive:
Therefore, PRP needs to be compared against an appropriate control—not simply against doing nothing.
A statistically significant result doesn't necessarily mean a patient feels substantially better.
We discuss the concept of the minimal clinically important difference, which asks whether the magnitude of improvement is large enough for patients to actually notice and value.
One of the major problems with the PRP literature is lack of standardization.
Studies may differ in:
So when someone says, "Studies show PRP works," an important follow-up question is:
Which PRP? For which condition? Compared with what?
Corticosteroids can provide relatively rapid symptom relief through their anti-inflammatory effects.
PRP is intended to influence the biological environment and may have a slower onset of benefit.
For some conditions, PRP appears to provide more durable improvement than corticosteroid.
For others, the difference is minimal or uncertain.
Neither treatment should automatically be considered "better" without considering the diagnosis and evidence.
No.
PRP does not introduce stem cells into the injured tissue.
It uses the patient's own platelets and the biological mediators associated with them.
This claim requires caution.
Laboratory and animal studies demonstrate potentially beneficial effects on cartilage biology.
Some human studies demonstrate improvements in pain and function.
But symptom improvement is not the same as proven regeneration of normal articular cartilage.
Clinical improvement should not automatically be interpreted as cartilage regeneration.
Before undergoing PRP, consider asking:
PRP represents an exciting area of orthopedic and regenerative medicine.
There is legitimate science behind the concept.
There are biologically active molecules within platelets that can influence tissue healing.
But the clinical evidence is far more nuanced than many advertisements suggest.
For some conditions, PRP appears beneficial.
For others, the benefit is modest or uncertain.
And for certain conditions—including Achilles tendinopathy and tennis elbow—recent placebo-controlled evidence does not demonstrate a meaningful advantage over placebo.
The most important lesson is that PRP should be viewed as a treatment option—not a cure-all.
The right question isn't:
"Does PRP work?"
The better question is:
"Does PRP work for my specific condition, using this particular preparation and treatment protocol, and is the expected benefit worth the cost and alternatives?"
That is the conversation patients should be having with their physicians.