Leukocyte Rich or Leukocyte Poor PRP. Which Type Is Right for Your Joint

Key points

• A 2026 network meta-analysis in the Journal of Orthopaedic Surgery and Research pooled 21 randomised trials and 2,254 patients comparing leukocyte-rich PRP, leukocyte-poor PRP, hyaluronic acid and placebo for knee osteoarthritis, rated the certainty of evidence low, and concluded leukocyte-poor PRP may be the more prudent choice to reduce post-injection reactions, with leukocyte-rich remaining a valid option.

• A systematic review of 5 randomised hip osteoarthritis trials of 43 to 111 patients each found leukocyte-poor PRP outperformed leukocyte-rich, and a single injection outperformed multiple.

• A 2019 randomised trial in the American Journal of Sports Medicine of 57 athletes with patellar tendinopathy found 35 percent improved with leukocyte-rich PRP against 72 percent with leukocyte-poorand 71 percent with saline at 12 weeks, all with supervised loading.

• A 2025 meta-analysis of 26 randomised trials and 1,650 knees found higher platelet concentration,independent of white cell content, was linked to greater improvement, so leukocyte content is one variable among several.

If you want to know which type would suit your joint or tendon, message us on WhatsApp or email team@thewellnesslondon.com and a doctor will explain what they would use for you and why.

What the terms actually mean

When blood is spun in a centrifuge it separates into layers. Red cells sink, plasma rises, and between them sitsa thin band called the buffy coat that holds most of the white blood cells and a large share of the platelets.Leukocyte-rich PRP includes that buffy coat, so it carries a high concentration of platelets and a high concentration of white cells. Leukocyte-poor PRP takes only the plasma layer above it, with a lower platelet count and few white cells. Some systems allow the operator to choose, others produce one or the other bydesign, and most patients are never told which.

The white cells are the point of contention. Neutrophils release enzymes and inflammatory signals that in laboratory studies degrade cartilage and provoke an inflammatory response. The same signals may be exactly what a degenerate tendon, which has stopped healing, needs to restart repair. That is the theory. A joint linedwith cartilage is thought to prefer the quieter product, and a chronic tendon the louder one. The trials test how far the theory holds, and the answer is partly.

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What the joint evidence says

The knee is where leukocyte content has been studied most, and the 2026 network meta-analysis in the Journal of Orthopaedic Surgery and Research is the most complete summary. It pooled 21 randomised trials and 2,254 patients, comparing leukocyte-rich PRP, leukocyte-poor PRP, hyaluronic acid and placebo on WOMAC function at 6 months, pain, and short-term adverse events. Both forms of PRP outperformed hyaluronic acid and placebo. Between the two forms the functional difference was small and the certainty of evidence was rated low. The authors’ practical conclusion was that leukocyte-poor PRP may be the moreprudent choice to minimise post-injection morbidity, that leukocyte-rich remains a valid option, and that peak benefit is likely within 6 months with repeat treatment considered after that.

An earlier meta-analysis found leukocyte-poor PRP produced significantly greater WOMAC improvement than hyaluronic acid whereas leukocyte-rich did not, and a 2025 meta-analysis of 12 randomised trials confirmedleukocyte-poor PRP outperforms hyaluronic acid in knee osteoarthritis. Against that, a double-blindrandomised trial of 192 patients comparing the two head to head found leukocyte presence did not affect safety or efficacy. For the hip, the systematic review of 5 randomised trials found leukocyte-pooroutperformed leukocyte-rich. The direction across the joint literature is consistent even where the size of the difference is not.

Send your imaging on WhatsApp and a doctor will tell you which preparation the evidence supports for your joint and stage.

What the tendon evidence says, and where the theory fails

The theory that tendons want leukocyte-rich PRP has more logic than trial support. The 80-patient glutealtendinopathy trial that found PRP beat steroid at 2 years used leukocyte-rich PRP, and so did the 2025 UK trial that found it no better than saline. The 240-patient Achilles trial in JAMA that found PRP no better than shamused a single intratendinous injection. In tennis elbow, where the evidence for PRP over steroid is strongest across 26 trials and 1,877 patients, the included trials used both types, and a 2022 systematic review of 26studies found leukocyte-rich and leukocyte-poor were both effective when measured against the minimal clinically important difference.

The trial that most directly tested the theory in a tendon argued against it. The 2019 patellar tendinopathy trial in the American Journal of Sports Medicine randomised 57 athletes to ultrasound-guided leukocyte-rich PRP,leukocyte-poor PRP or saline, all followed by 6 weeks of supervised loading. At 12 weeks, 35 percent of theleukocyte-rich group had improved against 72 percent of the leukocyte-poor group and 71 percent of the saline group. The differences were not statistically significant in a trial of that size, but the group that receivedthe product the theory recommends did worst. A clinic that tells you tendons always need leukocyte-rich PRPis repeating the theory, not the trial.

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Leukocyte content is one of four variables

Which white cells are in the syringe matters less than most patients are led to believe, because it is one of four things that vary between preparations, and the others are rarely disclosed. Platelet concentration is the first.The 2025 meta-analysis of 26 randomised trials and 1,650 knees found higher platelet concentrations gave greater improvement, and the largest positive placebo-controlled knee trial, of 610 patients, used a product with 4.3 times the platelet concentration of whole blood. A 2026 meta-regression in Knee Surgery, SportsTraumatology, Arthroscopy found PRP characteristics influenced short-term results but could not separate their independent effects.

Activation is the second, whether the platelets are triggered to release their growth factors before injection or left to activate in the tissue. Volume and number of injections is the third, and for the hip a single injection outperformed multiple. Red cell contamination is the fourth, since red cells in a joint are irritant and a poorlyseparated preparation carries them. Consensus frameworks now ask trials to report all of these, and the 2026network meta-analysis called for the same. A patient can reasonably ask a clinic for the same information, anda doctor-led clinic should be able to give it.

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Six questions about the product before you accept the injection

These apply whichever clinic you see, including ours. The answers tell you whether the clinic understandswhat it is injecting.

• Is the preparation leukocyte-rich or leukocyte-poor, and why was that chosen for my joint or tendon.

• What is the platelet concentration relative to my whole blood, and does the system measure it or assumeit.

• Is the preparation activated before injection, and with what.

• What volume is injected, how many injections are planned, and which trial supports that number for my condition.

• How is red cell contamination minimised, and can I see the preparation before it is injected.

• Which commercial system or protocol is used, so that I can look up what it produces.

If the answer to the first question is that it does not matter, the clinic has not read the hip trials. If the answer to the second is a shrug, the clinic does not know what it is injecting.

Our doctors put it this way. Leukocyte-poor for joints and a case by case decision for tendons is where the evidence sits. But the type of PRP matters less than whether the clinic knows which type it just gave you.

Message us on WhatsApp with your joint or tendon, your diagnosis if known, and any imaging, and a doctor will tell you what they would prepare and why.

What choosing the right type does not do

Choosing leukocyte-poor over leukocyte-rich does not turn a condition PRP does not help into one it does. Itdid not rescue ankle osteoarthritis, thumb base arthritis or refractory greater trochanteric pain in theirplacebo-controlled trials, and no formulation reattaches a torn tendon or regrows cartilage. The functional difference between the two types in knee osteoarthritis is small and the certainty of the evidence is low.Leukocyte-poor PRP still carries a lower platelet count in most systems, which is a trade-off, not a free improvement. PRP of any type is not routinely commissioned by the NHS and private medical insurance rarely covers it.

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What the preparation costs, and what an unknown one costs

Specialist central London clinics commonly charge from around £780 to £900 or more per image guided PRP injection including assessment, with a course of 2 to 3 taking a plan past £2,000. Outside central London PRPis advertised from around £250 to £500, and the cheaper the injection the less likely anyone can tell you its leukocyte content, platelet concentration or activation.

The reframing is that the price of a PRP injection buys a product, and a product with an unknown specificationis worth less than one with a known one, whatever it costs. A £300 injection of a preparation nobody can describe and an £800 injection of one chosen for your joint are not the same treatment at different prices.They are different treatments.

Care at The London PRP Clinic by The Wellness is doctor-led and priced below flagship central London rates,with your exact figure confirmed at the free suitability review once a doctor has decided which preparation, ifany, your case needs.

Ask about the cost for your joint on WhatsApp and we will explain what the review covers.

The free suitability review

Every enquiry here starts with a free, doctor-led suitability review rather than a booking. A GMC-registereddoctor assesses you and gives one of two answers. Either you are approved for treatment, with a named preparation, a stated number of injections, and realistic expectations for your joint or tendon, or you are not approved, with an honest explanation of what would serve you better.

We decline a meaningful share of the people who enquire. That is deliberate. A clinic that approves everyone isoptimising for bookings, not outcomes.

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Why people choose The London PRP Clinic by The Wellness

• An 87 percent patient success rate across treatments.

• More than 187 five star reviews.

• Every treatment performed by a GMC-registered doctor.

• 100 supervised treatments completed by every clinician before they treat a patient here unsupervised.

• A 32 percent average density increase reported in our hair restoration programme.
  
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Frequently asked questions

What is the difference between leukocyte-rich and leukocyte-poor PRP

Leukocyte-rich PRP includes the buffy coat layer from centrifuged blood, giving high platelet and high white cell concentrations. Leukocyte-poor PRP takes only the plasma layer, with fewer white cells and usually fewer platelets. White cells add an inflammatory signal that may help a degenerate tendon and may irritate a joint.

Which type of PRP is best for knee arthritis

A 2026 network meta-analysis of 21 trials and 2,254 patients found both types beat hyaluronic acid and placebo, with a small functional difference and low certainty. It concluded leukocyte-poor PRP is the moreprudent choice for fewer post-injection reactions, while leukocyte-rich remains valid.

Which type of PRP is best for tendons

The theory favours leukocyte-rich for chronic tendons, but the trial that tested it most directly, in 57 athletes with patellar tendinopathy, found leukocyte-rich did worst. The tennis elbow evidence supports both types. Itis a case by case decision, not a rule.

Does leukocyte-rich PRP cause more pain after injection

Trials and the 2026 network meta-analysis report a trend towards more post-injection pain and swelling withleukocyte-rich preparations, though a 192-patient double-blind trial found no difference in safety. Soreness for several days is common with either type.

Does platelet concentration matter more than leukocyte content

It may. A 2025 meta-analysis of 26 trials found higher platelet concentration gave greater improvement in knee osteoarthritis, and the largest positive placebo-controlled knee trial used PRP at 4.3 times whole blood concentration. Leukocyte content is one of four variables, alongside concentration, activation and volume.

How do I find out which type of PRP a clinic uses

Ask which commercial system or protocol they use and whether the preparation is leukocyte-rich orleukocyte-poor, then ask why that was chosen for your joint. A doctor-led clinic should answer directly. Ifnobody can tell you, that is useful information about the clinic.

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References

• Journal of Orthopaedic Surgery and Research, 2026. Leukocyte-rich versus leukocyte-poor platelet-richplasma and hyaluronic acid for knee osteoarthritis, a systematic review and network meta-analysis of 21randomised trials. https://link.springer.com/article/10.1186/s13018-026-06689-4

• Cureus, 2024. Almutairi and Alazzeh. Efficacy and safety of PRP intra-articular injections in hip osteoarthritis, a systematic review of randomised clinical trials.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11578636/

• American Journal of Sports Medicine, 2019. Scott et al. Platelet-rich plasma for patellar tendinopathy, arandomised controlled trial of leukocyte-rich PRP or leukocyte-poor PRP versus saline. Summarised in Ochsner Journal, 2021. https://www.ochsnerjournal.org/content/21/3/232

• Journal of Experimental Orthopaedics, 2025. Platelet-rich plasma compared to viscosupplementation inthe treatment of knee osteoarthritis, a meta-analysis of 26 randomised trials. Summary athttps://myorthoevidence.com/AceReport/Show/platelet-rich-plasma-compared-to-viscosupplementation-in-the-treatment-of-knee-osteoarthritis

• Knee Surgery and Related Research, 2025. Intraarticular leukocyte-poor platelet-rich plasma injection is more effective than intra articular hyaluronic acid injection in the treatment of knee osteoarthritis, a meta-analysis of 12 randomised trials. https://kneesurgrelatres.biomedcentral.com/articles/10.1186/s43019-025-00266-5

• ClinicalTrials.gov NCT02923700. Leukocyte-rich PRP vs leukocyte-poor PRP for the treatment of knee cartilage degeneration, a double-blind randomised controlled trial of 192 patients.https://clinicaltrials.gov/study/NCT02923700

• American Journal of Sports Medicine, 2022. Effectiveness of platelet-rich plasma for lateral epicondylitis,a systematic review and meta-analysis based on achievement of minimal clinically important difference.https://pmc.ncbi.nlm.nih.gov/articles/PMC9003647/

• Knee Surgery, Sports Traumatology, Arthroscopy, 2022. Long-term clinical efficacy of pure platelet-richplasma versus sham saline in knee osteoarthritis, a multicentre double-blind randomised trial of 610participants. https://delosportsmedicine.com/wp-content/uploads/2022/03/PRPLongTermEfficacyArticle.pdf

• Knee Surgery, Sports Traumatology, Arthroscopy, 2026. Younger age and platelet-rich plasmacharacteristics influence short-term outcomes in knee osteoarthritis, a systematic review with meta-analysis and meta-regression. https://pubmed.ncbi.nlm.nih.gov/42605960/

• American Journal of Sports Medicine, 2018. Fitzpatrick et al. The effectiveness of platelet-rich plasma injections in gluteal tendinopathy, a randomised double-blind controlled trial comparing a single PRP injection with a single corticosteroid injection. https://pubmed.ncbi.nlm.nih.gov/29293361/

• Journal of Bone and Joint Surgery, 2025. Atchia et al. Efficacy of platelet-rich plasma versus placebo for the treatment of greater trochanteric pain syndrome, a double-blinded randomised controlled trial, the HIPPO trial. https://pubmed.ncbi.nlm.nih.gov/39804899/

• JAMA, 2021. Kearney et al. Effect of platelet-rich plasma injection vs sham injection on tendon dysfunction in patients with chronic midportion Achilles tendinopathy, the ATM randomised clinical trial.https://pmc.ncbi.nlm.nih.gov/articles/PMC8278266

• Clinics in Shoulder and Elbow, 2025. Maroun et al. Platelet rich plasma versus corticosteroids for lateralepicondylitis, a meta-analysis of 26 randomised clinical trials. https://pubmed.ncbi.nlm.nih.gov/40077872/

• Central London clinic price lists for image guided PRP and steroid injections, accessed September 2026.

This article is for general information and does not replace a medical assessment. Speak to one of our doctors before deciding whether PRP, of any type, is right for you.