PRP (Platelet-Rich Plasma)

Mechanism of action:

• Platelets release growth factors: PDGF, TGF-β, VEGF, EGF, IGF-1
• These growth factors recruit stem cells and stimulate tissue repair
• Anti-inflammatory cytokines reduce local inflammation
• Concentrated platelets (3-8x baseline) amplify natural healing response
• Fibrin matrix provides scaffold for tissue regeneration

Key studies:

• Filardo et al. (2021): Meta-analysis of 30 RCTs showing PRP superior to hyaluronic acid for knee OA
• Gentile et al. (2020): Meta-analysis confirming efficacy for androgenetic alopecia
• Fitzpatrick et al. (2017): Systematic review of PRP for tendinopathy
• Everts et al. (2020): Review of PRP mechanisms in skin rejuvenation

Applications with evidence:

• Knee osteoarthritis - strong evidence (multiple meta-analyses)
• Hair loss (androgenetic alopecia) - moderate-strong evidence
• Tendinopathy (tennis elbow, patellar, Achilles) - moderate evidence
• Facial rejuvenation - moderate evidence
• Rotator cuff injuries - emerging evidence
• Wound healing - emerging evidence

PRP preparation variations:

• Leukocyte-rich (LR-PRP): Higher growth factors, more inflammatory
• Leukocyte-poor (LP-PRP): Less inflammatory, preferred for joints
• Platelet concentration: 2-8x baseline affects potency
• Activation method: Calcium chloride, thrombin, or freeze-thaw

Standard PRP preparation:

1. Blood draw: 15-60 mL depending on application
2. Centrifugation: Single or double-spin to concentrate platelets
3. Separation: Platelet-rich layer extracted (typically 3-10 mL)
4. Activation: Optional - calcium chloride or thrombin
5. Injection: Into target tissue under ultrasound guidance (for joints/tendons)

For knee osteoarthritis:

• 3 injections, 1 week apart (typical protocol)
• 4-6 mL per injection
• LP-PRP (leukocyte-poor) preferred
• Repeat course every 12-18 months as needed
• Best results in mild-moderate OA (Kellgren-Lawrence grade 1-3)

For hair loss:

• Monthly injections for 3-4 months initially
• Maintenance every 3-6 months
• Multiple small injections across scalp (0.05-0.1 mL per site)
• Often combined with microneedling
• Results visible after 3-6 months

For tendinopathy:

• 1-3 injections, 2-4 weeks apart
• Ultrasound-guided injection into tendon
• Avoid NSAIDs for 2 weeks before/after
• Relative rest for 1-2 weeks post-injection
• Physical therapy starting 2-4 weeks post-injection

For facial rejuvenation (Vampire Facial):

• PRP applied topically after microneedling
• Or injected directly into skin
• Series of 3-4 treatments, 4-6 weeks apart
• Maintenance every 6-12 months

Post-treatment:

• Avoid NSAIDs (ibuprofen, naproxen) - they inhibit platelet function
• Ice may be used for comfort but may reduce efficacy
• Light activity OK, avoid strenuous exercise for 48-72 hours
• Full activity typically resumed within 1-2 weeks

Common side effects (expected):

• Pain at injection site (24-72 hours)
• Swelling and stiffness (temporary)
• Bruising at blood draw and injection sites
• Mild inflammatory flare (actually indicates response)

Rare complications:

• Infection (very rare with autologous blood)
• Nerve injury (if injection technique poor)
• Tissue damage from needle
• No improvement (treatment failure rate ~20-30%)
• Calcification at injection site (rare)

Relative contraindications:

• Active infection
• Blood disorders (thrombocytopenia, platelet dysfunction)
• Anticoagulant therapy (relative - may need to hold)
• Cancer (theoretical concern about growth factors)
• Pregnancy
• NSAIDs within 1 week (reduces platelet function)

Important considerations:

• Results vary significantly between providers
• No standardized preparation protocol
• Quality depends on centrifuge, technique, platelet count achieved
• Not FDA-approved for most applications (used off-label)
• Insurance rarely covers (considered experimental)

Ideal candidates:

• Knee osteoarthritis (mild-moderate, K-L grade 1-3)
• Hair loss in early-moderate stages
• Chronic tendinopathy not responding to PT
• Those wanting natural/autologous treatment
• Athletes with overuse injuries
• People seeking skin rejuvenation without surgery

May not benefit:

• Severe osteoarthritis (bone-on-bone, K-L grade 4)
• Complete tendon tears (need surgery)
• Advanced hair loss (no follicles to stimulate)
• Those expecting immediate results
• People who can't afford multiple treatments

Better alternatives:

• For knee OA: Exercise, weight loss, hyaluronic acid (cheaper), eventual replacement
• For hair loss: Minoxidil/finasteride (cheaper, proven), transplant (more definitive)
• For tendons: Eccentric exercises, shockwave therapy (non-invasive)
• For skin: Retinoids, microneedling alone, laser treatments

What to measure:

• Pain scores (0-10 VAS before each treatment and at follow-ups)
• Function questionnaires (WOMAC for knee, DASH for upper extremity)
• Photography (same lighting/angle for skin and hair)
• Hair counts in standardized area (for alopecia)
• Range of motion measurements

Timeline:

• Baseline assessment: Before first treatment
• Short-term: 2-4 weeks post-treatment
• Medium-term: 3 months
• Long-term: 6-12 months

Signs it's working:

• Knee OA: Reduced pain, improved walking, less stiffness
• Hair: New growth visible at 3-4 months, density increase at 6 months
• Tendons: Decreased pain with activity, improved strength
• Skin: Improved texture, reduced fine lines, better tone

Red flags:

• Increasing pain after 1 week (may indicate infection)
• Fever or signs of systemic illness
• Severe swelling or redness
• No improvement after 3 treatments

Per treatment costs:

• Knee/joint injection: $500-1,500
• Hair restoration: $400-1,000 per session
• Facial rejuvenation: $500-1,500
• Tendon injection: $500-1,200

Full treatment course:

• Knee OA (3 injections): $1,500-4,500
• Hair (4 initial + maintenance): $2,000-5,000 first year
• Facial (3-4 sessions): $1,500-6,000
• Tendon (1-3 injections): $500-3,600

Cost considerations:

• Usually not covered by insurance (experimental)
• Some sports medicine practices offer packages
• Prices vary widely by region and provider
• Compare to alternatives:
• Hyaluronic acid injection: $300-500
• Hair transplant: $4,000-15,000
• Cortisone injection: $100-300
• Microneedling alone: $200-700 per session

Researchers:

• Dr. Allan Mishra - Orthopedic surgeon, pioneered PRP for tennis elbow
• Dr. Giuseppe Filardo - Leading researcher on PRP for knee OA
• Dr. Pietro Gentile - Extensive research on PRP for hair loss

Practitioners:

• Many sports medicine physicians and orthopedic surgeons offer PRP
• Dermatologists for hair and skin applications
• Regenerative medicine specialists

Note: Quality varies significantly between providers. Look for practitioners who measure platelet concentration and use ultrasound guidance for joint/tendon injections.

Common positive reports:

• "Finally got relief from knee pain after years of suffering"
• "Hair started growing back after 3 months"
• "My tennis elbow that wouldn't heal finally improved"
• "Skin looks more youthful without surgery"

Common complaints:

• "Expensive and insurance won't cover it"
• "Didn't work for my knee - needed replacement anyway"
• "Results took much longer than expected"
• "Hard to find a good provider"
• "Needed multiple treatments to see results"

Reddit/forum sentiment:

• Generally positive for knee OA in appropriate candidates
• Mixed for hair - some swear by it, others see nothing
• Athletes report good results for tendon issues
• Many frustrated by cost and lack of insurance coverage
• Consensus: find experienced provider, manage expectations

Often combined with:

• Microneedling - PRP applied after microneedling for skin ("vampire facial")
• Physical therapy - Essential for tendon/joint applications
• Hyaluronic acid - Some protocols combine with HA for knee OA
• Minoxidil - Topical minoxidil often continued with PRP for hair
• Exercise therapy - Strengthening crucial for joint applications

Timing considerations:

• Avoid NSAIDs 1 week before and 2 weeks after
• Avoid corticosteroids for 2-4 weeks before
• Physical therapy typically starts 2-4 weeks post-injection
• Space PRP sessions 2-4 weeks apart minimum

Related interventions:

• Shockwave Therapy - Alternative for tendinopathy
• Collagen - Supports tissue healing
• BPC-157 - Another regenerative peptide (less evidence)