PRP for Hair Loss: Evidence-Based Recommendations
Primary Recommendation
PRP combined with topical minoxidil 5% twice daily is the most effective evidence-based treatment for androgenetic alopecia, demonstrating 1.74-fold increase in hair density and 14.3-fold increase in hair diameter compared to baseline. 1
Treatment Protocol
Standard PRP Administration
- Deliver three intradermal scalp injection sessions spaced exactly one month apart (months 0,1, and 3) 1, 2
- Use 5-7 mL PRP per session with 30-gauge × 4 mm needles 2
- Inject at 90-degree angle, 2-4 mm depth, spacing injections 1 cm apart across mapped areas of hair loss 2
- Apply pharmaceutical-grade topical anesthetic before injection to minimize pain 2
- Maintenance injections every 6 months are required to sustain results long-term 1, 3
Critical Preparation Detail
Use nonactivated PRP—activation before injection is unnecessary and produces inferior results. Nonactivated PRP demonstrates 31% greater increases in hair count and total hair density compared to activated PRP. 1, 2
Concurrent Therapy
- Topical minoxidil 5% at 1 mL twice daily must be applied throughout the treatment period and continued indefinitely 4, 2
- Consider adding finasteride and multivitamin supplements as background therapy 2
- The triple combination (PRP + minoxidil + finasteride) represents the most effective evidence-based approach 3
Expected Outcomes and Timeline
Response Prediction
- Initial improvements become visible at 2-3 months of continuous therapy 2, 3
- A 25% improvement in hair density at 2 months predicts sustained response at 6 months 1, 2
Six-Month Results
- Hair density increases by 1.74 times 4, 2
- Hair diameter increases by 14.3 times 4, 2
- Telogen phase hair decreases by 9.3 times 2
- Mean increase of 33.6 hairs in target area and 45.9 hairs per cm² compared to baseline 5
Patient Satisfaction
- High overall patient satisfaction with average score of 7.29 on 0-10 scale 6
- 64% of patients report improvement in hair density, 57% report new hair growth, and 48% report less hair loss 6
- Patients rate likelihood of recommending PRP to friends at 8 out of 10 6
Efficacy Considerations
Best Candidates
PRP shows particular value in mild-to-moderate androgenetic alopecia cases, with more severe grades showing variable results. 2 Complex therapy (PRP with minoxidil) should be applied as early as possible for best results. 1
Comparative Efficacy
- Combination therapy with PRP and topical minoxidil 5% is significantly more effective than either monotherapy 2
- Both monotherapies are superior to placebo 2
- PRP is not superior to minoxidil alone in treating moderate grades of androgenetic alopecia when used as monotherapy 4
- Minoxidil monotherapy is better tolerated than PRP monotherapy due to less pain 4
Factors Affecting Outcomes
- Higher platelet numbers result in greater effect than lower numbers regarding hair density, follicle diameter, and terminal hair density 4
- Younger age, female sex, and whole-head administration are associated with improved PRP efficacy 7
- Double centrifugation produces better results than single centrifugation 7
Safety Profile and Adverse Effects
- Pain during injection is the primary complaint 2
- No major side effects noted during treatment 5
- Minimal morbidity and low cost 4
- PRP is generally safe and effective with high patient satisfaction 6, 8
Treatment Maintenance and Relapse
Continuous treatment is mandatory to maintain benefits—discontinuation results in loss of gains within months. 3 After 12 months without treatment, progressive hair loss becomes evident by 16 months. 5 Patients experiencing relapse require re-treatment. 5
Emerging Alternative: Platelet-Rich Fibrin (PRF)
PRF is emerging as a potentially superior alternative to PRP, offering theoretical advantages with similar efficacy and lower cost. 2 PRF demonstrates clinical efficacy in androgenetic alopecia with a similar safety profile to PRP, and is safe, easy, time and cost-effective. 4, 2
Evidence Quality and Limitations
The evidence for PRP remains somewhat controversial due to highly variable study protocols, preparations, and treatment intervals—standardized approaches are still evolving. 1 Studies show heterogeneity in preparations, protocols, treatment intervals, and many patients are not assessed for adequate length of time. 4 Improved and standardized study designs with larger samples, quantitative measurements, and longer follow-up periods are needed. 4
Monitoring Treatment Response
Use trichoscopy to evaluate hair density and diameter at 2,3, and 6 months. 1 Standardized before-and-after photographs and patient self-assessment questionnaires should also be employed. 1