What is Platelet-Rich Plasma (PRP) treatment?

Platelet-Rich Plasma (PRP): Comprehensive Overview

Definition and Composition

Platelet-Rich Plasma (PRP) is an autologous blood-derived concentrate containing 1.0-1.5 million platelets per microliter—significantly higher than the platelet count in whole blood—along with plasma proteins and growth factors that stimulate tissue regeneration and hair follicle proliferation. 1, 2

• PRP is prepared from the patient's own blood, making it an autologous treatment with minimal risk of allergic reactions or rejection 3, 4
• The concentrate contains multiple bioactive growth factors including transforming growth factor beta (TGF-β), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and various cytokines 2, 4
• Plasma proteins, particularly fibrin, create a scaffold structure that enables sustained, gradual release of growth factors over time 2

Mechanism of Action

PRP works by inducing proliferation of dermal papilla cells, increasing vascularization of perifollicular tissue, and accelerating the transition of hair follicles from the resting (telogen) phase to the active growth (anagen) phase. 2

• The concentrated growth factors enhance the body's inherent capacity to repair and regenerate hair follicles 5
• PRP increases the proliferative activity of hair follicle cells and improves hair morphology in patients with androgenetic alopecia 6
• Higher platelet concentrations directly correlate with greater improvements in hair density, follicle diameter, and terminal hair density 2

Preparation Protocol

The optimal PRP preparation uses a manual double-spin centrifugation method without activation, as nonactivated PRP demonstrates 31% greater increases in hair count and total hair density compared to activated PRP. 1, 7

• Autologous blood (typically 9-10 mL) should be drawn and processed immediately using standardized centrifugation protocols 1, 2
• The target platelet concentration is 1.0-1.5 million platelets per microliter 1, 2
• Activation before injection should be avoided, as it produces inferior clinical outcomes 1, 7

Treatment Protocol for Androgenetic Alopecia

The standard treatment protocol consists of three intradermal scalp injection sessions spaced exactly one month apart (at months 0,1, and 2), delivering 5-7 mL of PRP per session, with mandatory maintenance injections every 6 months to sustain results. 1, 7, 2

Initial Treatment Phase:

• Administer 3-5 treatment sessions spaced one month apart 1, 2
• Use 30-gauge × 4 mm needles for injection 1
• Apply pharmaceutical-grade topical anesthetic before injection to minimize pain 1
• Employ point-by-point injection technique at 90-degree angle, 2-4 mm depth, spacing injections 1 cm apart across mapped areas of hair loss 1

Concurrent Therapy:

Combination therapy with PRP plus topical minoxidil 5% (1 mL twice daily) is significantly more effective than either monotherapy, and both monotherapies are superior to placebo. 6, 1, 7

• Apply topical minoxidil 5% at 1 mL twice daily throughout the treatment period and beyond 1
• Consider adding finasteride and multivitamin supplements as background therapy 1

Maintenance Phase:

• Continuous treatment is required to maintain benefits—discontinuation results in loss of gains 1, 7
• Maintenance PRP injections every 6 months are necessary to sustain results 1, 7

Expected Outcomes and Timeline

Initial improvements in hair density become visible at 2-3 months, with a 25% improvement at 2 months predicting sustained response at 6 months. 1, 7

Quantifiable Results at 6 Months:

• Hair density increases by 1.74 times baseline 1, 7
• Hair diameter increases by 14.3 times baseline 1, 7
• Telogen phase hair decreases by 9.3 times 1
• Hair density reaches peak levels around 3 months (170.70 ± 37.81 hairs/cm²) 3

Patient Satisfaction:

• Mean patient satisfaction rating of 7.1 on a scale of 1-10 3
• Patients report visible changes on clinical photographs and dermoscopy 6

Monitoring Treatment Response

Assessment should include standardized before-and-after photographs, trichoscopy to evaluate hair density and diameter, and patient self-assessment questionnaires. 7, 2

• Key indicators of positive response include increased hair density per cm², increased hair shaft diameter, decreased proportion of telogen hairs, and improved patient satisfaction scores 2
• Trichoscopy can objectively measure density and diameter ratios 7

Optimal Patient Selection

Mild to moderate androgenetic alopecia responds most favorably to PRP treatment, with more severe grades showing variable results. 1

• Complex therapy (PRP with minoxidil) should be applied as early as possible for best results 7
• Individual genetic factors significantly influence response to platelet concentrate therapy 2

Safety Profile and Adverse Effects

Pain during injection is the primary complaint, though PRP is generally well-tolerated with no remarkable major side effects. 1, 3

• Mild pain or discomfort during the injection process is common 6
• No significant swelling, bruising, or scar hyperplasia reported in clinical studies 6
• PRP is relatively safe as an autologous preparation 5

Common Pitfalls and Treatment Failure

Low platelet concentration, inadequate injection volume, or insufficient treatment frequency are the primary causes of treatment failure. 2

• Ensure platelet concentration reaches 1.0-1.5 million platelets per microliter 1, 2
• Deliver adequate volume (5-7 mL per session) 1, 2
• Maintain proper treatment frequency (monthly during initial phase, every 6 months for maintenance) 1, 7
• Avoid activating PRP before injection, as this reduces efficacy by 31% 1, 7

Emerging Alternative: Platelet-Rich Fibrin (PRF)

PRF is emerging as a potentially superior alternative to PRP, offering theoretical advantages including lower cost, easier preparation, and similar clinical efficacy with a comparable safety profile. 6, 1

• PRF demonstrates clinical efficacy in androgenetic alopecia with positive patient satisfaction scores 6
• PRF is described as a safe, easy, time and cost-effective adjuvant modality for managing androgenetic alopecia 6
• PRF is particularly valuable for mild cases of androgenetic alopecia 6

Applications Beyond Hair Restoration

PRP has expanding applications in dermatology including skin rejuvenation, lip augmentation, acne scar treatment, and perioral wrinkle reduction. 6, 8

• For lip rejuvenation, microinjections of 0.15 mL are delivered point-by-point into lips over three monthly sessions 6
• Topical PRP reduces superficial perioral wrinkles and restores dermal matrix when used at home for 12 weeks 6
• Combining PRP with laser therapies, microneedling, dermal fillers, and autologous fat grafting produces synergistic effects 8

Current Limitations

The evidence for PRP remains somewhat controversial due to highly variable study protocols, preparations, and treatment intervals—standardized approaches are still evolving. 7

• There is no universally standardized protocol or recommendations for the number of PRP sessions required 5
• Further large-scale studies are needed to optimize PRP preparation and administration procedures 5, 9
• Long-term follow-up of objective hair loss outcomes is needed 9