PRP Hair Restoration: Good vs Poor Candidates

Which patients are good candidates for PRP hair restoration and who is unlikely to respond?

Candidacy comes down to one biological question, and it isn't about age, budget, or how badly someone wants their hair back: are there still living follicles up there capable of answering a growth-factor signal? If you can see short, fine, pale hairs in the thinning zone, you've got something to work with. If the skin is smooth and shiny, you're being asked to fertilize a parking lot.

Early to middle pattern loss with visible miniaturization: Strong candidate. Expect a modest gain in caliber and count over three to six monthly sessions, then maintenance every three to six months.

Smooth, shiny bald scalp or Norwood VI to VII: Poor use of the patient's money. The follicles are gone, so there's nothing left to stimulate.

Any scarring alopecia, active infection, platelet disorder, or anticoagulation: Don't treat. Injecting into active scarring inflammation can make things worse rather than simply doing nothing.

Thyroid disease, low ferritin, postpartum shedding, or rapid weight loss: Conditional. Fix the driver first, then reassess. Often the shedding settles on its own.

Core Principle

Platelet rich plasma preserves and improves the density of hair that still exists, and it does not regrow hair that is already gone.

What pattern and stage of hair loss responds best to platelet rich plasma injections?

Most people want a stage number, but the honest answer is closer to a mirror test than a chart. Part the hair under bright light and look for short, fine, pale hairs, because that's the population you're actually treating. The trial data clusters around early androgenetic loss for exactly that reason, and it thins out fast once you climb the grades.

Best-responding band: Norwood-Hamilton II to III and the earlier Ludwig grades, where miniaturization is still active.
Pooled result: About twenty-eight additional hairs per square centimeter after three to five monthly sessions, on low-quality, highly varied evidence.
Location beats grade: Vertex and mid-scalp hold their ostia for years; temples and frontal hairline lose follicles outright and disappoint.
Wrong diagnosis, wrong tool: Telogen effluvium reverses on its own, and alopecia areata is an immune problem that belongs with a dermatologist.

Established Fact

A pooled analysis of thirteen randomized trials found an average gain of roughly twenty-eight hairs per square centimeter after a standard course of three to five monthly sessions, on evidence its authors rated low quality and highly heterogeneous.

Why does the difference between a miniaturized follicle and a scarred one decide whether treatment can work at all?

Everything here hangs on whether the stem cell reservoir survived. A miniaturized follicle is fully intact and just running short, weak cycles, so the signals released from concentrated platelets have something to act on. A scarred one has been replaced by a fibrous tract, and you can't send instructions to a structure that no longer exists.

What you're checking	Miniaturized follicle	Scarred (cicatricial) follicle
Follicular ostia	Retained, with yellow dots	Lost, with smooth or ivory patches
Hair diameter diversity	Above 20% in men, 10% in women	Not the defining feature
Surrounding skin	Peripilar brown halo	Erythema, scaling, tufting from one opening
Patient symptoms	Painless, no complaints	Burning, itching, tenderness
What injection does	Extends anagen, delays catagen	Nothing, and can provoke koebnerization

Expert Note

A four millimeter punch biopsy read by a dermatopathologist settles an ambiguous scalp, and it is the cheapest test in the entire pathway relative to the months of destroyed follicles it prevents.

Which medical conditions, blood disorders, and medications rule a person out of treatment?

Exclusions come in two tiers, and mixing them up costs you in both directions: you turn away people you could have helped, or you treat someone you shouldn't have touched. The short list is genuinely non-negotiable. The longer list is where the actual judgment lives, and it's the one that shows up in clinic every week.

Absolute stop: Platelet dysfunction syndromes such as Glanzmann thrombasthenia and Bernard-Soulier, critical thrombocytopenia, sepsis or acute systemic infection, active cutaneous infection at the injection site, hemodynamic instability, and hematologic malignancy of the myeloid or platelet lineage.

If the platelets are defective or too few, spinning the blood concentrates nothing useful.

Usually a stop: Warfarin, direct oral anticoagulants, and therapeutic heparin, which raise bruising and hematoma risk and usually flag a condition that deserves a physician's opinion first.

Low-dose aspirin, clopidogrel, and routine anti-inflammatories are softer; you can hold non-essential ones, but you never pause a secondary-prevention drug on a clinic's say-so.

Relative, and far more common: Uncontrolled diabetes, chronic liver disease, heavy smoking, long-term systemic corticosteroids, and active autoimmune disease, all of which blunt the healing response enough to make the result unpredictable.

Say this out loud before taking payment, not after the third session disappoints.

Defer: Recent or active cancer on precautionary grounds, systemic isotretinoin, recent chemotherapy, immunosuppressive regimens, plus pregnancy and breastfeeding, where there's no safety data and waiting costs the patient nothing.

The Legal Line

Consensus guidance holds that a previously investigated thrombocytopenia above fifty thousand per cubic millimeter, outside of hematologic malignancy, is not in itself a bar to treatment, though any significant abnormality on the blood count warrants investigation before the first draw.

How much do age and how long the shedding has been going on change the odds of a meaningful result?

Ask how long, not how old. A sixty-two year old whose crown started thinning eighteen months ago will often beat a thirty year old who's been shedding steadily since university, because what decides the outcome is how many follicles are still alive, not how many birthdays have gone by. Age does pull on the result, but it's the secondary lever.

Loss noticed recently, density still visible: The best window you'll get. Miniaturization is still reversible in a share of follicles and thickening is genuinely photographable.

Long-standing progression in the same area: The ceiling drops steeply. More of those follicles have finished the trip to fibrosis, which is why an identical three-session course produces a striking photo in one patient and an argument in another.

Aggressive loss in the late teens or twenties: Follicles respond well, but the androgenetic drive is strong and lifelong. Injections without a medical foundation underneath are bailing while the tap runs.

Senescent thinning past seventy: Diffuse caliber loss across the whole head rather than a pattern, and it responds modestly at best.

Worth Understanding

Gains begin to decline in the six to twelve months after the last session without maintenance, so a patient starting at twenty-eight is committing to two to four sessions a year potentially for decades.

What blood work, scalp examination, and imaging should happen before a course is booked?

The workup exists to answer one question before any money changes hands: is this scalp shedding for a reason injections can address, or for a reason a prescription or a diet change fixes faster and cheaper? Skip it and you'll spend three months treating an iron deficiency with needles.

Laboratory panel: Complete blood count with platelet count, serum ferritin, TSH with free T4, and vitamin D. In women showing acne, irregular cycles, or hirsutism, add total and free testosterone, DHEAS, and prolactin.
Ferritin in particular: The highest-yield single test in women, since low stores drive shedding even with normal hemoglobin. Thresholds in the literature run from about fifteen to seventy nanograms per milliliter, and many authors want above forty to seventy before they'll call a scalp ready.
Trichoscopy at 20x to 70x: Read hair diameter diversity, vellus to terminal ratio, peripilar signs, density, yellow and black dots, and above all whether follicular ostia are still there.
Pull test: Fifty to sixty hairs from several sites. Four or more coming away per pull points to an active effluvium that needs settling before you start.
Punch biopsy where indicated: Four millimeters, non-negotiable when there's scaling, erythema, tenderness, burning, tufting, or any hint of scarring.
Baseline documentation: Fixed-angle photography, consistent lighting, a consistent part line, a marked reference point, and a hair count per square centimeter in a reproducible target area.

Best Practice

Without standardized baseline photography and a hair count per square centimeter, the month-six review becomes a memory contest, and memory reliably favors whoever is holding the invoice.

How does candidacy differ between men with pattern balding and women with diffuse thinning?

Men and women show up with different geometry, and the geometry drives the whole plan. He has a defined zone with a border and an untouched fringe to compare against. She has a widening part across the entire mid-scalp with nothing adjacent to photograph as a control, which changes both the workup and the conversation about what success will look like.

Factor	Men with pattern loss	Women with diffuse thinning
Distribution	Regional: temples and vertex, stable occipital fringe	Diffuse mid-scalp, frontal hairline preserved
Treatment field	Defined zone with a clear border	The whole crown, no untouched comparison area
Non-androgenetic causes	Uncommon	Iron deficiency, thyroid disease, postpartum and post-contraceptive effluvium, PCOS, perimenopause, traction
Workup weight	Standard	Decisive, since skipping it penalizes women disproportionately
What success looks like	Denser vertex, defended frontier	A narrower part and better coverage, not a new hairline

The Deciding Factor

The outcome literature does not clearly favor either sex once stage and cause are matched, but a woman's diffuse distribution makes fixed-site density counts and part-line photography essential, since the improvement is spread thinly across a large area rather than concentrated in one obvious patch.

What actually happens to someone who is treated despite being a poor candidate?

Here's what makes this so easy to sell and so hard to catch: the usual outcome isn't injury, it's nothing. Four monthly sessions go by, the patient can't tell whether anything changed, and gets told to be patient and book maintenance. With no baseline photograph, nobody can settle the argument, and the whole thing can roll on for a year.

Financial exposure: At roughly four hundred to nine hundred dollars a session, a course plus a year of maintenance runs two to five thousand dollars.
Physical harm: Uncommon and usually minor. Injection-site pain, headache, swelling, bruising, and pinpoint bleeding, with infection rare given autologous material.
The real exception: Needling an undiagnosed scarring alopecia can drive koebnerization, and treating over an untreated folliculitis seeds infection deeper.
The worst cost: Nine months of injections in someone with frontal fibrosing alopecia or an evolving lichen planopilaris is nine months the effective therapy wasn't running.

Where It Goes Wrong

A failed course does not compromise later options, since a subsequent transplant or medical regimen proceeds normally, so the damage is confined to money, time, and whatever the underlying condition destroyed in the meantime.

Where should a person who is not a candidate be directed instead?

A refusal is only worth anything if it comes with a direction. Most people turned away from injections have never been properly offered the cheaper, better-evidenced options sitting right next to them. And plenty of refusals aren't permanent at all, they're a review date with homework attached.

Pattern loss too advanced for growth factors: Topical minoxidil at two or five percent, oral finasteride at one milligram daily in men, and low-dose oral minoxidil or anti-androgens such as spironolactone in women under specialist supervision.

Follicles gone but the donor fringe is stable: Follicular unit extraction or strip transplantation. A Norwood V to VI patient with dense occipital coverage is a far better surgical candidate than an injection candidate.

Anything inflammatory or odd: Scaling, erythema, tenderness, burning, pustules, tufting, eyebrow loss, or an abnormal hairline pattern goes to a dermatologist without delay, since the treatment window there is measured in months.

Abnormal labs or signs of hyperandrogenism: A general practitioner or endocrinologist first. Correcting the thyroid or the ferritin is frequently the entire answer.

The Practical Move

Book a declined patient for reassessment in three to six months after the iron, thyroid, medication, or dermatitis has been dealt with, rather than sending them away permanently, because conditional refusals often return as the candidates who actually get a result.

Written by Daniel Zengel

Medical Writer

Daniel Zengel is the principal owner of H-SHOT and H-Shot Training, a medical writer covering platelet-rich plasma and hair restoration. He draws on more than a decade in pharmaceutical and medical device roles, with a focus on regenerative medicine and the device standards and provider training that make PRP results consistent from clinic to clinic.