# Inside PRP: the shot comes from your blood *What PRP Contains | PRP Injections Gilbert* > See what platelet rich plasma is made from, what happens to your blood, and what the prepared shot can and cannot show. Have the sore area examined before you weigh a blood-based shot. The exam can show whether the trouble lies in a joint, tendon, muscle, or nerve. That answer matters more than the name of a treatment. Doctors use PRP to mean platelet rich plasma: blood from your arm is spun to keep clear liquid with extra clot-forming platelets. These small blood parts also carry signals the body uses during repair. That gives doctors a reason to study PRP, not proof that it will help you. ## PRP can contain different amounts of blood cells Spinning separates heavier red cells from the clear liquid the clinician keeps. One method may gather more clot-forming platelets than another. Some methods also keep more white cells, the blood cells that fight germs. More white cells may mean more soreness after a joint shot. Research suggests that link, but it hasn’t shown the best amount for every body part. The letters PRP don’t describe one fixed mixture. ## Blood counts cannot predict how much relief you will feel A blood count can show how many clot-forming platelets are in the prepared shot. It cannot show how your knee or shoulder will feel later. Only studies of people can compare soreness and movement after care. Some studies show less soreness, and others show no clear benefit. Results from knees don’t settle shoulder questions or reveal your response before treatment. Your outcome cannot be known in advance. ## Your exam still guides the choice The clinician needs to know what hurts, which motions worsen it, and what care you’ve tried. Your medicines and other health problems also matter. An earlier X-ray may help explain arthritis or another cause. Ask how people with the same problem felt after PRP, how well they moved, and when the study checked them. A useful answer separates what was shown from what is only hoped for. You can decide without treating hope as proof. ## Sources 1. In a controlled laboratory study, blood from five healthy donors was processed through three commercial PRP systems (MTF Cascade, Arteriocyte Magellan, Biomet GPS III). Platelet, red-cell and TGF-beta1 concentrations did not differ significantly between systems, but white-cell counts and PDGF-alpha-beta, PDGF-beta-beta and VEGF concentrations differed significantly across all three. Cascade produced leukocyte-poor PRP while GPS III and Magellan produced leukocyte-rich PRP with correspondingly higher white cells and growth factors. Castillo TN, Pouliot MA, Kim HJ, et al. — [Comparison of growth factor and platelet concentration from commercial platelet-rich plasma separation systems](https://pubmed.ncbi.nlm.nih.gov/21051428/). *American Journal of Sports Medicine*, 2011. DOI: 10.1177/0363546510387517. 2. The PAW classification was proposed because PRP preparation protocols 'vary widely between authors and are often not well documented in the literature, making results difficult to compare or replicate'. It sorts preparations by three variables: the absolute number of Platelets, the manner of Activation, and the presence or absence of White cells - the three levers that make two injections both called 'PRP' materially different products. DeLong JM, Russell RP, Mazzocca AD — [Platelet-rich plasma: the PAW classification system](https://pubmed.ncbi.nlm.nih.gov/22738751/). *Arthroscopy*, 2012. DOI: 10.1016/j.arthro.2012.04.148. 3. A narrative review of PRP concluded that the literature suggests leukocyte-rich PRP is more beneficial in tendinopathies while pure (leukocyte-poor) PRP is more beneficial in cartilage pathology - but stated plainly that different PRP preparations have not been directly compared head-to-head in ANY pathology, and that the PRP type used is frequently not even stated in published research. Collins T, Alexander D, Barkatali B — [Platelet-rich plasma: a narrative review](https://pubmed.ncbi.nlm.nih.gov/34040800/). *EFORT Open Reviews*, 2021. DOI: 10.1302/2058-5241.6.200017. 4. A systematic review that screened 876 studies and extracted standardised data from 33 commercially available PRP systems and protocols found that final product concentrations of platelets, white cells and growth factors varied widely between systems, as did the preparation protocols themselves. Platelet concentration correlated directly with the volume of blood drawn and with the centrifugal force of the device. The authors called the heterogeneity between separation systems something that 'must be resolved for proper study of this promising treatment'. Fadadu PP, Mazzola AJ, Hunter CW, et al. — [Review of concentration yields in commercially available platelet-rich plasma (PRP) systems: a call for PRP standardization](https://pubmed.ncbi.nlm.nih.gov/30992411/). *Regional Anesthesia and Pain Medicine*, 2019. DOI: 10.1136/rapm-2018-100356. 5. A systematic review of 105 clinical PRP studies in orthopaedics published 2006-2016 found that only 11 (10%) described the preparation protocol clearly enough for another investigator to repeat it, and only 17 (16%) reported any quantitative metric of the final PRP composition. The authors concluded that the current reporting of PRP preparation and composition does not allow the PRP products actually delivered to patients to be compared between studies. Chahla J, Cinque ME, Piuzzi NS, et al. — [A Call for Standardization in Platelet-Rich Plasma Preparation Protocols and Composition Reporting: A Systematic Review of the Clinical Orthopaedic Literature](https://pubmed.ncbi.nlm.nih.gov/29040132/). *Journal of Bone and Joint Surgery (American)*, 2017. DOI: 10.2106/JBJS.16.01374. ## When soreness still limits your day QC Kinetix offers consultations about regenerative treatments after simple care has not helped enough. That means non-surgical options which may use blood taken from your arm and prepared at the clinic. PRP is short for platelet rich plasma: your blood is spun to gather clear liquid with extra clot-forming platelets. A medical provider, the clinician who examines you, can explain likely causes, side effects, and whether an option fits. The address is 1100 S. Dobson Rd., Suite 210, Chandler, AZ 85286, and you can call (602) 837-PAIN about current scheduling. Schedule a free consultation: --- Clear answers for a sore joint. Plain answers about sore joints, care at home, PRP injections Gilbert, and when an exam may help. Plain help for joint soreness, PRP choices, and nearby care for Gilbert readers. This site is operated by the owners of the QC Kinetix Phoenix-area clinics, including the Chandler location it recommends, and the business benefits when readers book a consultation. © 2026 Gilbert Platelet Ledger. This is general health education; it is not medical advice for an individual's diagnosis or treatment decision.