What Is PRP Platelet Rich Plasma? | A Clinical Overview

Sep 05, 2025

Oscar Tellez

What Is PRP Platelet Rich Plasma? Defining a Core Tool in Regenerative Care

For many clinicians, what is PRP platelet rich plasma might seem like a question that’s already been answered. But as the use of PRP has evolved — from sports medicine to orthopedics and outpatient regenerative care — so has the need for clarity.

PRP isn’t a one-size-fits-all solution. It’s not a stem cell therapy, nor is it a simple blood product. It sits in a unique space between pharmacologic symptom control and surgical intervention — and its precise role in tissue recovery depends on how well we understand its biologic profile.

This blog takes a deeper look at what PRP actually is, how it's classified, where it fits into treatment workflows, and why understanding its composition is critical for clinical success.

What Is PRP Platelet Rich Plasma — Really?

PRP platelet rich plasma is autologous blood plasma that contains a supraphysiologic concentration of platelets — typically 3 to 6 times the patient’s baseline count. It’s created by centrifuging a blood sample to isolate the plasma layer rich in platelets while minimizing red cells and (in some protocols) leukocytes.

Unlike steroid injections or NSAIDs, PRP does not suppress inflammation artificially. Instead, it delivers endogenous signaling molecules — such as PDGF, TGF-β, VEGF, and EGF — that help regulate local inflammation, stimulate fibroblasts, and support matrix regeneration.

The biologic value of PRP lies in its ability to initiate or reset healing processes in damaged tissues, particularly where healing has stalled.

The Evolution of PRP in Clinical Use

PRP was first introduced in transfusion medicine and surgical hemostasis. But its role expanded in the 1990s and early 2000s, particularly in:

Oral and maxillofacial surgery
Orthopedic soft tissue procedures
Sports injury recovery
Tendon and ligament repair

Today, PRP is widely used in outpatient settings — including sports clinics, pain practices, and regenerative centers — as a conservative, biologically active treatment option.

Its appeal? PRP is derived from the patient’s own blood, processed with minimal manipulation, and reinjected into the site of injury or degeneration. There are no synthetic agents, no immunogenic materials, and no long-term systemic exposure.

Mechanisms of Action: What PRP Actually Does

To fully understand what is PRP platelet rich plasma, clinicians need to move beyond general statements like “it promotes healing.”

Here’s a clearer breakdown of how PRP works at the tissue level:

🧠 In the synovium (e.g., early-stage OA):

Downregulates inflammatory cytokines like IL-1β and TNF-α
Modulates MMP activity to preserve cartilage matrix
May support hyaluronic acid production and lubrication

💪 In tendons and ligaments:

Stimulates tenocyte proliferation
Enhances Type I collagen synthesis
Promotes organized ECM remodeling after microtrauma

🦴 In subchondral bone or BMLs:

Improves microvascular flow
Supports osteoblast activity
May reduce pain via downregulation of nociceptive signals

PRP doesn’t regenerate tissue overnight. But it changes the local environment in a way that supports biologic repair — especially in early and mid-stage conditions.

Regulatory Classification and Misconceptions

In the U.S., PRP is regulated by the FDA under 21 CFR 1271 as a human cell, tissue, and cellular/tissue-based product (HCT/P) — provided it's:

Autologous
Minimally manipulated
Intended for homologous use

It is not classified as a drug or biologic requiring a BLA — unless altered or combined with other materials.

That’s important because many clinics misuse the term “PRP” to describe products that:

Contain added biologics or exosomes
Are expanded or enzymatically modified
Include proprietary mixes without clarity on composition

Physicians must ensure that what is PRP platelet rich plasma in their clinic aligns with regulatory definitions and ethical practice.

PRP Classifications by Content

Another key point: “PRP” isn’t a single formulation. It varies by platelet count, leukocyte content, and fibrin architecture.

✅ The four major types:

P-PRP (Pure PRP): Low leukocytes, no fibrin — ideal for joints and OA
L-PRP (Leukocyte-rich): Higher WBC count — sometimes used in tendon repair
P-PRF (Pure PRF): Platelet concentrate with fibrin scaffold, no WBCs
L-PRF (Leukocyte and platelet-rich fibrin): Includes immune cells, forms a solid fibrin matrix

These distinctions affect inflammation, cellular recruitment, and how PRP interacts with tissue. That’s why choosing the right type matters as much as choosing PRP in general.

What PRP Is Not

As PRP usage grows, so does confusion around what it includes. Here’s what PRP platelet rich plasma is not:

❌ It’s not stem cell therapy. PRP contains no living mesenchymal stem cells.
❌ It’s not exosome therapy. PRP releases exosomes from platelets but does not contain isolated extracellular vesicles.
❌ It’s not a biologic drug. PRP is processed at the point of care without pharmacologic additives.
❌ It’s not standardized across clinics. Platelet counts, leukocyte ratios, and preparation methods all vary.

Understanding what PRP can and cannot do helps set realistic expectations for patients and improves treatment planning.

Combination Use and Surgical Integration

PRP isn’t always a standalone therapy. It is increasingly used in combination with:

Microfat or BMAC for orthopedic biologic stacking
Tendon graft integration
ACL or rotator cuff repair support
Post-op inflammation control and recovery

In these cases, PRP serves as a biologic primer or adjunct — not the sole treatment. Its value comes from its ability to modulate healing responses when other factors are at play.

Clinical Implementation Tips

To use PRP effectively, physicians should:

Understand their system’s output: Platelet concentration, cell ratios, volume
Know the indication-specific goals: Is this anti-inflammatory or pro-regenerative?
Use validated kits: Avoid DIY systems with inconsistent results
Educate patients clearly: Set realistic expectations for timing and outcome

Systems like Tropocells PRP, available via Accretion Portal, offer monocyte-rich, neutrophil-poor plasma in a closed, easy-to-use system — helping clinicians stay focused on outcomes, not preparation.

Final Word: Why Defining PRP Matters Now More Than Ever

So, what is PRP platelet rich plasma in 2025?

It’s not a mystery fluid. It’s a defined, regulated autologous biologic with real clinical applications — provided it's used thoughtfully.

With the surge in biologic therapies, physicians have a responsibility to know what they’re injecting, how it works, and what the patient can expect. PRP isn't a cure-all — but when prepared and applied appropriately, it remains one of the most versatile tools in regenerative medicine.

Evaluate PRP Systems You Can Trust

Accretion Portal offers PRP kits, tubes, and related accessories for regenerative medical use.

View our available products or contact us to discuss clinical needs and product compatibility.