PRP therapy produces a 30 to 40 percent increase in hair density based on controlled clinical data. Platelet-rich plasma is not a cure for hair loss, but it is the most studied non-surgical injection treatment available in 2026 for slowing miniaturization and thickening existing hairs.
This article is for informational purposes only and does not constitute medical advice.
What PRP Does to Hair Density
PRP works by concentrating the growth factors in your own blood and injecting them directly into the scalp. The platelets release PDGF, VEGF, TGF-beta, and other signaling proteins that stimulate follicular stem cells, increase blood supply to the dermal papilla, and prolong the anagen (growth) phase of the hair cycle.
The result is not new hair from nothing. PRP thickens miniaturized hairs that are still alive but producing progressively thinner, shorter strands. Under a dermatoscope, these hairs show increased shaft diameter and improved follicular unit density after treatment.
Clinical Density Numbers
Published studies consistently report density improvements in the 30 to 40 percent range when measured by trichoscopy or phototrichogram at 6 to 12 months post-treatment.
| Study / Source | Patients | Density Increase | Measurement Period |
|---|---|---|---|
| Gentile et al. (2015) | 23 | 33.6% | 12 months |
| Alves & Grimalt (2016) | 25 | 29.4% | 6 months |
| Hausauer & Jones (2018) | 40 | 31-37% | 6 months |
| Schiavone et al. (2020) | 64 | 34.5% | 12 months |
| Meta-analysis range | -- | 30-40% | 6-12 months |
These numbers represent the average across responders and non-responders. Individual results vary based on age, extent of miniaturization, platelet concentration, and protocol used.
What 30-40% Actually Looks Like
A 35 percent increase in density does not mean you go from bald to full coverage. It means existing thin hairs become thicker and existing follicular units produce slightly more visible output. On a patient who starts at 60 hairs per square centimeter in a thinning zone, a 35 percent improvement brings that to approximately 81 hairs per square centimeter.
Visually, patients report:
- Thinning areas appear less transparent under direct light
- Part lines look narrower
- Styling covers more scalp
- Hair feels thicker when running fingers through it
Patients with large bald zones (Norwood 5+) where follicles have been dormant for years will see minimal benefit. PRP cannot resurrect dead follicles.
Who Gets the Best Results
PRP performs best in a specific patient profile. Understanding where you fall determines whether the investment makes sense.
Ideal PRP Candidates
| Factor | Best Response | Poor Response |
|---|---|---|
| Norwood stage | 2-3 | 5-7 |
| Hair loss duration | Under 5 years | Over 10 years |
| Miniaturization level | Moderate (30-50%) | Severe (80%+) |
| Age | 25-45 | Over 60 |
| Scalp condition | Mild thinning, visible hairs | Slick bald, no vellus hairs |
| Concurrent treatment | On finasteride/minoxidil | No other treatment |
Patients already taking finasteride or minoxidil who add PRP tend to see the most dramatic improvements. PRP works synergistically with DHT blockers because the follicles are already stabilized and primed to respond to additional growth factor stimulation.
Expected Timeline
Results from PRP follow a predictable schedule:
- Weeks 1-4: No visible change. Growth factors are activating cellular pathways.
- Months 2-3: Reduced shedding is often the first noticeable sign.
- Months 3-6: New vellus hairs and thickening of existing hairs begins.
- Months 6-12: Peak density improvement reaches the 30-40% range.
- Months 12+: Gradual regression without maintenance sessions.
Cost Per Session and Total Investment
PRP costs between $500 and $2,000 per session in the United States. The wide range reflects differences in platelet preparation systems, provider type, and geographic location.
PRP Cost Breakdown
| Component | Cost Range |
|---|---|
| Single PRP session | $500 to $2,000 |
| Initial series (3-4 sessions) | $1,500 to $6,000 |
| Annual maintenance (1-2 sessions) | $500 to $3,000 |
| First-year total | $2,000 to $8,000 |
| Ongoing annual cost | $500 to $3,000 |
Clinics using double-spin centrifuge systems that achieve higher platelet concentrations (5x to 8x baseline) tend to charge more, but also report better outcomes. Single-spin kits produce lower concentrations and are associated with more inconsistent results.
How to Evaluate a PRP Provider
Not all PRP is the same. The quality of the preparation directly affects outcomes. When choosing a provider, ask:
- What centrifuge system do they use? Double-spin systems (Eclipse, Harvest, EmCyte) produce higher platelet concentrations.
- What is the platelet concentration? A minimum of 4x baseline concentration is considered therapeutic. Below that, results are unreliable.
- How many sessions are in the protocol? Providers recommending only one session are unlikely to deliver measurable results.
- Do they combine PRP with other treatments? Combination with microneedling, ACell, or exosomes may enhance outcomes.
PRP Limitations
PRP has clear boundaries. It does not regrow hair in completely bald areas. It does not replace the need for finasteride or minoxidil in progressive androgenetic alopecia. It requires ongoing maintenance sessions to sustain results.
Patients who discontinue PRP after the initial series typically see a gradual return to baseline over 12 to 18 months. This is not a one-time fix.
For patients beyond early-stage loss, a hair transplant addresses bald areas that PRP cannot help. PRP and transplant surgery work well together: PRP maintains and thickens native hair while transplanted grafts fill in bare zones.
Next Steps
The density improvement PRP delivers is real and measurable, but it depends heavily on starting point. If you are in the early stages of thinning, PRP combined with medical therapy offers a meaningful non-surgical path.
To find out where you fall on the Norwood scale and whether PRP is appropriate for your current stage, use the free AI analysis tool at myhairline.ai/analyze.
For details on how often to schedule follow-up treatments, see our PRP maintenance session guide.