The Ultimate Guide To Platelet-Rich Plasma Therapy (PRP)
In the last decade, thousands of dermatologists have started offering platelet-rich plasma (PRP) therapy as a treatment for hair loss. At first glance, PRP seems like an enticing therapy: a hands-free, drug-free approach to improve our hair thinning…
…but with a $1,000+ price tag, is the therapy worth it? Is PRP right for all hair loss sufferers? And if platelet-rich plasma therapy does work, how much hair can we expect to regrow?
This ultimate guide to platelet-rich plasma therapy uncovers the answers. Here we’ll reveal how platelet-rich plasma therapy works, how it compares to similar therapies, and what most dermatologists don’t tell you about their PRP “before-after” photos.
We’ll also reveal how hair regrowth from PRP depends largely on your form of hair loss, whether you combine PRP with other treatments, and the type of PRP your dermatologist provides (Acell, etc.).
If you’re considering PRP as a hair loss treatment, this guide will help you determine if the costs make sense for your situation and, if so, how to select the right provider.
PRP Therapy: Highlights
- Effort. Medium (requires a few dermatology appointments, but is otherwise a hands-free therapy)
- Expectations. According to studies, regrowth can occur in as little as 3 months.
- Response rate: 80%+
- Regrowth rate: this varies depending on if PRP is done alone or alongside other therapies.
- PRP (alone): 25-30%
- PRP + finasteride: +1%
- PRP + microneedling: +5%
- PRP + minoxidil: +5%
- PRP + microneedling + minoxidil: +5-10%
- PRP + ACell: no studies (yet), but anecdotes suggest better results than PRP alone
- PRP (alone): 25-30%
- Cost. $1,000-$4,000+
- Problems. Expensive; real-world results often don’t match those of studies; similar mechanisms targeted with massaging and microneedling; results vary wildly depending on the clinic; results contingent upon continued sessions
PRP is effective for androgenic alopecia and alopecia areata, but it’s expensive and requires ongoing injections to maintain results. It works best as an adjunct treatment alongside other hair loss therapies, and while it has helped both men and women, evidence suggests that it’s less effective for females overall. If you’re going to try PRP, don’t just go to any clinic; rather, vet your cosmetic surgeon by asking them a list of questions we’ve suggested (below).
What is platelet-rich plasma therapy (PRP)?
Platelet-rich plasma therapy (PRP) is an injection-based therapy. It’s the injection of a modified version of our own blood into a tissue site – with the goal to accelerate healing, reduce scarring, and improve injury outcomes.
PRP has been used for dentistry, facial reconstruction surgery, orthopedics, sports injuries, acne scarring, and fat grafting. But in the last decade, it’s been given serious attention as a potential treatment for thinning hair.
How does PRP work?
PRP therapy is a multi-step process that involves drawing a sample of our blood, separating out its platelets, concentrating those platelets, and then re-injecting those platelets into a targeted location (like our scalp).
If you’re considering PRP, the procedure usually takes around an 30-90 minutes, and the process looks something like this:
- Obtain blood from the patient
- Centrifuge once – under a low speed – to separate out platelet-rich plasma from the blood
- Remove anything that isn’t plasma
- Centrifuge again
- Repeat step 3
- Mix the solution to make it uniform
Why focus on platelets?
Our blood volume contains roughly 55% plasma, 40-45% red blood cells, 6% platelets, and 1% white blood cells. Whenever our tissues incur a wound – for example, a paper cut – an inflammatory reaction begins, and our bodies will send blood to our injury site to initiate repair.
Interestingly, our platelets – which constitute just 6% of our blood volume – are responsible for a huge part of the entire repair process. Specifically, platelets do two things:
- Platelets help clot a wound to prevent excessive bleeding
- Platelets carry with them dozens of growth factors, all of which help to coordinate the entire healing process.
This begs the question: what if we could concentrate our platelets so that instead of sending only 6% of platelets to a wound tissue, we could send a much higher percentage? Would we see better injury outcomes? Would we see less scarring?
Well, this is exactly what platelet-rich plasma therapy does. In fact, recent advents in “centrifugation” – or the swirling, mixing, and separation of platelets from our blood – have enabled dermatologists to achieve blood platelet concentrations higher than 94%+. That’s a huge jump from the 6% typically carried within our normal blood volume.
And as of today, it seems like platelet concentrations do improve injury outcomes and scarring. Decades of studies show that, on average, if we concentrate high levels of plasma and send that plasma to an injury site, we can improve injuries, reduce scar tissue, and in doing so, maybe even regrow some hair.
How, exactly, does PRP improve hair loss?
There are several growth factors carried within plasma linked to hair growth, most notably:
- Platelet-derived growth factor
- Transforming growth factor
- Vascular endothelial growth factor
- Epidermal growth factor
- Fibroblast growth factor
- Connective tissue growth factor
- Insulin-like growth factor (IGF-1)
And when injected into balding scalp tissues, the arrival of these growth factors can do a few things:
- They reactivate dormant hair follicles and encourage them to reenter the anagen phase, thus increasing hair counts.
- They prevent hair follicles from entering the catagen phase or undergoing cell apoptosis (programmed cell death).
- They help to resolve longstanding inflammation and reduce scar tissue surrounding miniaturizing hair follicles, thereby increasing the hair thickness of miniaturized hairs.
- The promote blood vessel growth around the hair follicles to aid in hair regeneration.
Isn’t this similar to how massaging and microneedling work?
Yes. PRP’s mechanisms overlap with one of the ways by which massaging and microneedling improve hair loss: they both increase the number of growth factors in balding scalp regions. But, they do it in slightly different ways.
Massaging and microneedling first generate acute inflammation (i.e., micro-wounding), which then increases growth factors, which then helps to promote hair recovery. The order of operations is as follows:
Massaging / microneedling >> evokes micro-inflammation >> evokes platelets / growth factors >> decreases scarring proteins / increases angiogenesis >> reduces perifollicular fibrosis >> improves blood flow to miniaturizing hair follicles / increases follicle growth space >> increases hair growth
But there’s a key difference between PRP and these two therapies. With massaging and microneedling, you need to first evoke inflammation to increase growth factors to a wound site. With platelet-rich plasma, you essentially skip that first step, and instead, you simply inject platelets directly into the tissue of your choosing.
When it comes to balding scalp tissues, we can think of the mechanistic difference between these therapies as this:
Now, there is some wounding involved in PRP procedures. But that wounding / acute inflammation is a consequence to the injection of the platelets. In this way, PRP is sort of like a supercharged microneedling or massage session – only with many more platelets present.
Is platelet-rich plasma therapy effective?
This is a tricky question to answer.
If forced to give a one-word answer, then yes. Most studies on PRP show positive outcomes for hair loss. But if you’re going to invest thousands of dollars into the therapy, there are caveats of which you should be made aware.
The reality is that PRP’s effectiveness for regrowth depends on the study you reference and how you define the term, “effective”. Moreover, PRP efficacy varies greatly by:
- Hair loss type (i.e., androgenic alopecia, alopecia areata, etc.)
- Whether we combine PRP with other treatments (i.e., minoxidil, finasteride, microneedling)
- The type of PRP procedure (i.e., PRP alone, PRP + Acell, etc.).
We’ll cover all of this below. First, we’ll start with PRP’s issues. Then, we’ll dive into PRP’s benefits (and its effects on our hair).
Problem #1: most PRP studies have a high risk of bias
Most PRP studies are conducted by dermatologists who offer PRP procedures at their clinics. That creates an incentive to achieve positive results – because those positive results might encourage patients to do the procedure at their specific clinic.
However, this problem isn’t necessarily game-ending. In fact, nearly all hair loss research contains some level of bias. For instance, despite our efforts to control for bias in our own study on the massages, technically you could argue that because this site conducted it, our results are at risk of bias, too.
In any case, there are plenty of well-controlled studies on platelet-rich plasma and hair loss. We’ve filtered for these. But if you go digging through the literature and find a PRP study with crazy results, just know that if it wasn’t included in our analysis, there’s probably a good reason why.
Problem #2: most platelet-rich plasma studies aren’t standardized
Nearly every PRP study has a different patient profile (i.e., ages and hair loss severities), methodology (i.e., injection methods, rounds, treatment regions), trial duration (i.e., three months versus two years), and hair assessment method.
For instance, here are just a few ways PRP studies have measured hair loss “improvements” (ranked from worst to best).
- Hair tug tests (i.e., when an investigator yanks at a subject’s hair before and after treatment, then counts the number of hairs that fell out)
- Reduction in hair fall (i.e., hair shedding collected in the shower, by patients, pre- and post- treatment)
- Patient satisfaction scores (i.e., when a patient fills out a survey saying whether they’re happy with the treatment)
- Independent visual assessments (i.e., when a dermatologist eyeballs photos to give their input on hair improvements)
- Follical unit survival rates (for PRP + hair transplant studies) (i.e., how many transplanted hairs survived the transfer)
- Hair thickness (i.e., the change in the diameter of hair shafts in a specific scalp region)
- Terminal/vellus hair ratio (i.e., the number of thick and healthy versus thin and wispy hairs in a specific region)
- Hair counts (i.e., when a region is marked – usually with a temporary tattoo – to count hairs before and after treatment)
To be fair, this isn’t just a problem with PRP; it’s a problem with all of hair loss research. It’s why literature reviews have a hard time drawing conclusions about most treatments – because there are rarely apples-to-apples comparisons.
But again, we’ve sorted through all the PRP studies we could find to standardize the research (as best we can) and give you ballpark assessments of regrowth rates (i.e., increases to hair count in balding regions).
Problem #3: platelet-rich plasma therapy likely requires ongoing treatments
When you look into the research on minoxidil or finasteride, studies show that within 3-12 months of quitting either drug, your hair loss will return to what it was prior to the intervention. So, how long will results hold for platelet-rich plasma after quitting?
Well, it’s unclear how long results will last after you stop doing PRP treatments, but evidence suggests that a percentage of people will start seeing their hair return to baseline after a year.
Out of all PRP studies, the one with the longest follow-up period (two years) included 20 patients. Interestingly, four of them experienced a relapse in hair loss one-year post-PRP. In fact, their androgenic alopecia progressed beyond their pre-trial hair counts by the 16-month mark. This suggests that for about 20% of people, PRP’s effects start to wane 12-18 months after the treatment.
This wouldn’t be such an issue if the procedure were cheap, but it isn’t: several therapeutic rounds of PRP cost $1,000-$4,000+. So, if you’re going to give this procedure a try, make sure you’re financially comfortable with the investment.
Problem #4: PRP might not work for every person with hair loss
Out of all the research on PRP, only two studies found that PRP was an ineffective treatment option. One study was on females with androgenic alopecia. The other study was on men with advanced androgenic alopecia (Norwood gradients 4+).
If you were to ask me why the first study failed to produce results, I would say that it was probably because (like most women with hair loss) the females in that study likely had other undiagnosed hair loss types (like telogen effluvium / hair loss related to a chronic condition).
And as far as the study on men with advanced androgenic alopecia (AGA) – we need to keep in mind that the investigation team only did two rounds of PRP injections. For what it’s worth, in all of the PRP studies which saw improvement, a minimum of three PRP injection rounds were performed. So, it’s likely that either this study didn’t do enough injections to see results, or that men with advanced AGA needed several more injections before PRP begins to repeat significant benefit.
Problem #5: most PRP studies don’t measure PRP by itself
In fact, the overwhelming majority of studies measure PRP alongside other hair loss treatments – like minoxidil, finasteride, or even a hair transplant. So, it’s important to delineate between the studies you reference when evaluating whether PRP is right for you (we’ve done this below).
This also brings up another problem: dermatologists showcasing their PRP results online often don’t tell you something important: that they’re showing you PRP results alongside drugs like minoxidil and finasteride.
This is incredibly disingenuous, and I suggest that if you’re shopping around for a PRP clinic, you call ahead and ask the doctor if the results they showcase on their website are from PRP alone. If they are, great. If they’re not, but they’re labeled to make it seem as such, then that means these dermatologists are intentionally misleading prospective patients, and they should lose your business (and their license to practice).
While we might’ve just painted a problematic picture for PRP, this isn’t the whole story. In fact, PRP is an incredibly effective treatment for hair loss under the right circumstances. This is all covered below.
PRP has shown great promise for the hair loss disorder alopecia areata. This is an autoimmune condition that leads to hair loss in patchy spots throughout the head. In some cases, it can advance to complete baldness (alopecia universalis).
In fact, studies show that PRP is very effective in treating at least 70% of alopecia areata cases. Here are some of the really promising photos (source):
PRP alone (no other treatments)
When looking at PRP as a standalone treatment, most studies measuring hair counts suggest that the average patient will regrow 15 hairs per square centimeter (i.e., half the size of a penny). That’s about a 25-30% regrowth rate at 3-6 month follow-ups.
Quantitatively, that’s pretty impressive. For a benchmark, most studies on finasteride show just a 10% increase in hair count over two years.
Across studies, some of the less quantitative outcomes for PRP alone (at least at the 3-6 month mark) are:
- Patients report about a 75% increase in hair quality and thickness, and a decrease in the rate of hair loss.
- Patients usually perform better on the hair pull test, meaning that when they pull on a clump of the patient’s hair, fewer hairs came out compared to control groups.
- Patients report somewhat high satisfaction with the procedure at month three of follow up
Finally, a common trend mentioned among researchers is that PRP treatment seems to be more effective for patients with less severe forms of AGA. So, if you’re in the early stages of hair loss, PRP might be a great option for you.
PRP + hair transplantation
In one study examining hair transplantation, two areas with 50 grafts each(not a lot to measure, especially for hair transplantation) were compared with or without PRP injections. The area with PRP had, on average, 46.75 units that survived compared to the non-PRP which had, on average, 41 units that survived.
While this isn’t that drastic of an increase – we have to keep in mind that transplant procedures are incredibly costly… and that means that every hair follicle unit counts.
So, if you’re considering a hair transplant, you’ve spent the finances to secure a skilled surgeon, and you still have some extra spending money you’d like to throw into improving your results – do it alongside PRP. Chances are your hair transplant survival rates will improve, as will your overall hair count.
PRP + microneedling
In this study, 30 male participants received 6 PRP injections following microneedling sessions. At the six month follow-up, the average patient had a hair density increase of about 30%. This study also noted that the most significant improvement was seen in patients with less severe AGA.
PRP + minoxidil or PRP + finasteride
In this study comparing the efficacy of PRP + minoxidil and PRP + finasteride, while both outcomes were deemed effective, the PRP + minoxidil treatment actually achieved significantly better results than the PRP + finasteride group. In fact, the PRP + minoxidil group showed five-fold better hair increases versus the PRP + finasteride group.
Now, you might read these results and think that makes no sense. Finasteride is clinically more effective than minoxidil. So, why would PRP + minoxidil outperform PRP + finasteride?
Well, the devil is in the details. For one, the sample size of each PRP subgroup was less than 15 people. So, it’s possible these differences might’ve been due to statistical noise which would’ve canceled itself out with subgroups of 150+ people.
And secondly, while a five-fold improvement might sound drastic, we’re actually dealing with the law of small numbers here. Yes, PRP + finasteride saw an additional hair count lift of 1% versus 5% for the PRP + minoxidil group. And yes, that is technically a five-fold improvement. But in all reality, that’s just a few percentage points better.
PRP + minoxidil + microneedling
In this study comparing PRP + minoxidil + microneedling versus minoxidil alone, the earlier treatment proved to be much more effective than the latter, although exact numbers were not given in this study to show this. However, we can assume that PRP + minoxidil + microneedling is probably better than PRP + minoxidil, and that PRP + minoxidil is probably better than PRP alone.
PRP + Acell
PRP + Acell is a relatively new procedure that a lot of PRP practitioners are offering now. Acell is a protein matrix derived from pig bladder (you read that right) that creates a “scaffold” for new hairs. Acell essentially offers a platform by which all of our growth factors (and hair) can cling to. It also helps to stimulate stem cell activity.
[Note: since ACell is made from pig, people allergic to pig products should notify their physicians about their allergy prior to the treatment.]
There doesn’t seem to be any studies measuring the results of PRP + Acell compared to PRP alone, so it’s hard to objectively say whether it increases the effectiveness of PRP.
Are there any risks to PRP?
At least so far, there haven’t been any severe risks reported. However, some milder symptoms have been noted during and shortly after the procedure:
- Infection (rarer)
- Scarring or calcification of the injection site (for those with a propensity toward keloid scarring) (rarer)
- Blood vessel or nerve injury (rarer)
Who’s a good candidate for PRP? Who’s a bad candidate?
Androgenic alopecia treatments vary depending on your (1) finances, (2) willingness to invest time into a therapy, and (3) comfortability with FDA-approved drugs. Compared to some of the other AGA specific treatments, like standardized scalp massages and microneedling, PRP is a pricey option. At the same time, PRP is a lot less time consuming than microneedling or massaging because you may only go into a clinic for a handful of injection rounds before you start seeing results.
You are a great candidate for PRP if you…
- Are comfortable with the financial investment and ongoing treatments
- Want to stack PRP alongside other treatments in your hair loss regimen – like microneedling, massaging, minoxidil, or finasteride
- Are going to get a hair transplant and want to optimize your outcome of the procedure
- Have early-stage to mild AGA (and relatively small areas of hair loss)
- Have alopecia areata
- Are a poor candidate / do not want to try traditional hair loss medications
- Are physically healthy in general
You are not a great candidate for PRP if you…
- Do not want to spend thousands of dollars on the procedure
- Have advanced AGA and aren’t willing to commit to several rounds (and months-to-years) of injections
- Are a female with androgenic alopecia alongside conditions like hypothyroidism (treat that first!)
- Do not want to keep reinvesting money into a procedure that might not prove effective after a year.
- Have a bleeding disorder with clotting factor deficiencies or low platelet counts
- Use blood thinners
- Have a liver disorder
- Have a recent cancer history or sepsis (blood infection)
- Are a heavy smoker, alcoholic, or illicit drug user
- Have low blood pressure or chronic user of steroids
Do PRP study results hold true in the real world?
When evaluating any hair loss therapy, it’s important to note that, sometimes, study results don’t match up to real-world results. On hair loss blogs and forums, there’s sometimes an inkling that this might be the case with PRP.
For starters, while there are positive patient stories with PRP, there are also many anecdotes of patients who tried PRP without success. This video is a perfect example. And if you dig deeper, you’ll probably find more negative than positive anecdotes.
This can be confusing – as most of the literature tends to describe PRP as seemingly beneficial. And even more troublesome, it’s also worth noting that I’ve spoken with dozens of readers who’ve tried PRP… and most of them have also reported negligible improvements.
This begs the question: is PRP that effective? And regardless of the answer, why might there be a discrepancy between studies’ results and patient reports?
What could explain the discrepancies between PRP studies and real-world results?
For starters, it’s actually unclear if there are clinical versus real-world discrepancies for PRP. For instance, it’s possible that PRP treatments might just suffer from the “Yelp effect”. This is when someone with a negative experience is far more likely to leave a public review versus someone with a positive experience.
So, PRP might just be one of those treatments that have collected negative reviews over a period of years – much like finasteride and its reports of sexual side effects.
Secondly (and this is the more important point to make), clinical research does not always depict reality. For instance, while a 25-40% increase in hair count from PRP looks great on paper, it doesn’t always translate to cosmetic results.
This tends to be a problem with even the “best” FDA-approved treatments. Just take a look at these five men who did combination treatments of minoxidil, finasteride, laser combs, and even hair transplants – and their results after one year.
I’ll save you the suspense: their final “after” photos are darkened to obscure just how minimal their hair changes are. And, for the hundreds (to thousands) of dollars each of the men spent, their hair seems more-or-less cosmetically unchanged.
(Note: that video is just one of the reasons why, for most AGA sufferers, I recommend approaches like massaging / microneedling as a baseline for any regimen. Not only do these therapies enhance other hair loss treatments, but also without their inclusion, you’re statistically likely to see no cosmetic improvements from your other treatments).
Thirdly, we just learned that without follow-up sessions, PRP results will fade for 20% of patients starting 12-18 months after their last round of injections. So, if you’re reading a review of someone who got PRP once four years ago and never saw results (or is experiencing continued hair loss) – you’ll know that it’s probably because they didn’t do enough injection rounds and they didn’t keep up with the therapy.
In any case, it’s worth noting that of the readers with whom I’ve communicated, the ones who tried PRP + Acell all reported positive results. While there aren’t yet studies validating this combination therapy, it seems to be the most promising from an anecdotal standpoint (if that means anything to you).
How to choose the right PRP practitioner
If you’re going to invest $1,000+ into platelet-rich plasma, don’t give your money to the first PRP clinic you find.
Instead, find a few clinics near you that offer the procedure and make sure they have a proven track record. That means they should have a website with PRP before-after photos.
Make a list of these clinics. Then, call each clinic and ask if their online photos are of PRP alone or of PRP + finasteride / minoxidil.
If the photos are of PRP alone, great! If they’re of PRP + multi-therapies but advertised to represent only PRP… then hang up, cross them off your list, and consider reporting them the clinic to the Better Business Bureau.
Doing this should eliminate 60-70% of providers.
Next, call the remaining providers and ask about their PRP techniques. You’ll want to find a clinic that offers 1-4+ months between injection rounds. If someone offers you a package of 10 PRP sessions spaced out as one injection round per week, that goes against the literature’s recommendations (and our understanding of wound-healing timelines) – and you should probably find another provider.
Moreover, the actual PRP product that a clinic uses will vary by volume, number of injection rounds, color, platelet count, leukocyte count, and protein content. The best PRP providers will offer double-spin centrifugation preparation with an activator like thrombin or calcium chloride. While some evidence suggests that “platelet activators” are not necessary, they also don’t seem to hurt the procedure. In any case, it’ll be good to speak with your provider about all of this – so you can get a feel of whether they can actually answer these questions. If they can’t, then cross them off your list.
Lastly, ask your remaining clinics if they offer PRP + Acell. If they do (and the costs aren’t prohibitive), then this might be a better option versus PRP alone. If they don’t, it’s not the end of the world – and chances are you’ll still see benefit from the procedure.
Following this process should leave you a few great PRP clinic options. And, as long as you’re willing to commit to injections every 4-6 months, you should see a considerable lift in hair count… especially if you’re combining platelet-rich plasma with other therapies.
Platelet-rich plasma therapy is effective for both androgenic alopecia and alopecia areata, but the procedure is cost-prohibitive and requires repeated clinic visits to see sustained results. These factors are big turnoffs for most hair loss sufferers considering PRP as a treatment option.
PRP works best as an adjunct treatment alongside other hair loss therapies. So, don’t just try PRP as the only thing to help your hair. We recommend combining it with massaging and/or microneedling, and (if you’re comfortable), FDA-approved drugs (especially minoxidil) to maximize results. And, if you can, try to find a clinic that provides PRP + Acell.
While PRP can help both male and female hair loss sufferers, preliminary evidence suggests that it’s just not as effective for females. However, this might be because of the added complexities of female AGA – and the fact that women are so frequently misdiagnosed with AGA but instead actually have hair shedding disorders related to underlying chronic conditions.
Be careful about clinic selection for PRP. For instance, the photos you’ll see on most dermatology websites offering PRP are from patients doing PRP + finasteride / minoxidil (rather than PRP alone). The equivalent would be if I advertised a before-after photo of someone doing massaging + finasteride, but decided to position the photo as if the results were only from massaging. It’s just bad business. So, be aware of this. Call all clinics to confirm the regimens of their highlighted patients.
If you’re seeing improvements from PRP, chances are you’ve already navigated through this mess to find a good provider. So, steer the course and keep us posted with your progress!
Rob English is a researcher, medical editor, and the founder of perfecthairhealth.com. He acts as a peer reviewer for scholarly journals and has published four peer-reviewed papers on androgenic alopecia. He writes regularly about the science behind hair loss (and hair growth). Feel free to browse his long-form articles and publications throughout this site.