--- topic: "PRP (Platelet-Rich Plasma)" title: "What is PRP and how does it work?" order: 1 description: "How platelet-rich plasma is prepared and used for healing, hair restoration, and skin rejuvenation." question: "What is PRP (platelet-rich plasma) and how does it work?" answer: "PRP is a concentrate of your own platelets and growth factors that may speed tissue repair, but results vary with how it is prepared." actions: - "Ask the clinic how its PRP is prepared (spin speed, platelet count, leukocyte content, activation), as these change results [4]." - "Expect an in-office visit: a blood draw of about 15–60 mL, 15–30 minutes of preparation, then injection into the target area [1]." cautions: - "PRP is not FDA-approved as a drug; it is used as a medical procedure, with FDA-cleared devices for preparing it." - "Two trials using 'PRP' may use very different products, so one study's results may not apply to another clinic's treatment [4]." confidence: 2 confidenceNote: "Supported by reviews of growth-factor biology and a dermatology systematic review; this page cites no trials, and PRP products differ widely." evidenceSummary: rctCount: 0 observationalCount: 0 metaAnalysisCount: 1 replicated: false newestStudyYear: 2021 references: - id: "1" pmid: "33096812" url: "https://pubmed.ncbi.nlm.nih.gov/33096812/" title: "Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020" authors: "Everts P, Onishi K, Jayaram P, Lana JF, Mautner K" year: 2020 journal: "International Journal of Molecular Sciences" - id: "2" pmid: "32295047" title: "Systematic Review of Platelet-Rich Plasma Use in Androgenetic Alopecia Compared with Minoxidil, Finasteride, and Adult Stem Cell-Based Therapy" authors: "Gentile P, Garcovich S" year: 2020 journal: "International Journal of Molecular Sciences" - id: "3" pmid: "25722595" title: "Principles and Methods of Preparation of Platelet-Rich Plasma: A Review and Author's Perspective" authors: "Dhurat R, Sukesh M" year: 2014 journal: "Journal of Cutaneous and Aesthetic Surgery" - id: "4" pmid: "34040800" url: "https://pubmed.ncbi.nlm.nih.gov/34040800/" title: "Platelet-Rich Plasma: A Narrative Review" authors: "Collins T, Alexander D, Barkatali B" year: 2021 journal: "EFORT Open Reviews" --- PRP (platelet-rich plasma) is a concentrate made from your own blood that contains a high concentration of platelets and growth factors. It is used in orthopedics, dermatology, and aesthetics to promote tissue repair and regeneration. PRP is not FDA-approved as a drug, but it is widely used as a medical procedure because it uses a patient's own biological material. FDA-cleared devices exist for preparing PRP, and the procedure is performed in clinics across the United States and worldwide. ## How PRP Is Prepared The PRP process involves three basic steps: 1. **Blood draw** -- A small amount of blood (typically 15-60 mL) is drawn from the patient's arm, similar to a routine lab draw [1]. 2. **Centrifugation** -- The blood is placed in a centrifuge and spun at high speed. This separates the blood into three layers: red blood cells at the bottom, a "buffy coat" of white blood cells and platelets in the middle, and platelet-poor plasma on top [3]. 3. **Concentration and injection** -- The platelet-rich layer is extracted, resulting in a concentration of platelets 3-5 times higher than normal blood levels. This concentrate is then injected directly into the target area [1]. The entire preparation takes about 15-30 minutes and is typically done in-office. ## Growth Factors in PRP Platelets contain alpha granules that release several key growth factors upon activation [4]: - **PDGF (Platelet-Derived Growth Factor)** -- stimulates cell replication and blood vessel formation - **TGF-beta (Transforming Growth Factor)** -- promotes collagen synthesis and tissue remodeling - **VEGF (Vascular Endothelial Growth Factor)** -- stimulates new blood vessel growth - **EGF (Epidermal Growth Factor)** -- promotes cell growth and differentiation - **IGF-1 (Insulin-Like Growth Factor)** -- mediates cell growth and repair These growth factors work together to accelerate the body's natural healing cascade [4]. ## Common Applications PRP is used across several medical fields: - **Joint healing** -- Injected into damaged joints, tendons, and ligaments to reduce pain and promote tissue repair, particularly in knee osteoarthritis and rotator cuff injuries [1]. - **Hair restoration** -- Injected into the scalp to stimulate dormant hair follicles and promote hair growth in androgenetic alopecia [2]. - **Skin rejuvenation** -- Applied topically after microneedling or injected into the skin to stimulate collagen production and improve skin texture [2]. ## Preparation Variables That Affect Outcomes Not all PRP is created equal. Several variables in preparation significantly influence clinical results [4]: - **Centrifuge speed and time** -- Different protocols produce different platelet concentrations. Single-spin protocols yield lower concentrations (2-3x baseline), while double-spin protocols can achieve 5-8x baseline [3]. - **Leukocyte content** -- PRP can be leukocyte-rich (LR-PRP) or leukocyte-poor (LP-PRP). LR-PRP contains white blood cells that may increase inflammation, which can be beneficial for tendon injuries but detrimental in joint spaces [4]. - **Activation method** -- Platelets can be activated with calcium chloride, thrombin, or simply by exposure to collagen at the injection site. The activation method affects growth factor release kinetics [1]. - **Volume and platelet count** -- There is no universal standard for the "ideal" platelet concentration. Studies use widely varying protocols, which contributes to inconsistent results across clinical trials [4]. Understanding these variables is important when evaluating PRP studies, as two trials using "PRP" may actually be using very different products [4].