PRP (platelet-rich plasma)

PRP is plasma prepared from a person's own blood and enriched in platelets.¹ This article assesses the general areas in which PRP is used, in particular the effects studied for hair loss without a transplant, the findings on skin appearance, and the risks. It does not give a preparation recipe, a number of sessions or an individual treatment schedule. The changes reported in research are not a guarantee of the result any particular person will obtain.

What is PRP?

PRP is the abbreviation of "platelet-rich plasma".¹ The components of blood taken from a person are separated and the portion concentrated in platelets is used.¹ The word autologous means that the blood used comes from the same person. That word alone does not explain the content of the preparation, its effectiveness or its safety.^1,2

Are platelets and stem cells the same thing?

Platelets take part in clotting and carry various growth factors.¹ The roles of these substances in communication between cells, tissue repair and blood-vessel formation are under investigation.¹ The biological rationale for using PRP arises from these relationships; but an effect shown in the laboratory does not on its own show how much a person's hair or skin will change.¹

PRP and products containing stem cells are not the same thing.¹ That PRP can affect cells in tissue does not mean that stem cells are transferred during the procedure; bone-marrow-derived cell concentrates and PRP are treated separately in the scientific literature.¹ Nor would it be correct to draw that distinction by saying PRP contains no cellular component at all; besides platelets, varying amounts of leucocytes and other blood components can be present in the preparation.¹

Is every PRP preparation the same?

PRP is not a single fixed content. The method of preparation, the concentration of platelets, the leucocyte content and features such as the activation that triggers the release of substances from platelets can all vary.¹ That these features are not always reported in the same detail in research also limits comparison.¹

The use of the same name therefore does not show that the products studied are identical to one another. A favourable result in one study does not mean that a result of the same size can be expected from every preparation called PRP.¹ Conversely, the existence of differences in preparation does not show that PRP is ineffective; it requires knowing, when a result is read, which preparation was studied, for what purpose and by which measure.¹

What changes are expected, and what are not?

Do the areas of use rest on the same evidence?

Besides hair loss and skin appearance, PRP is studied in different fields such as orthopaedics, sports medicine and wound healing.¹ Each of these is a separate clinical question. Research carried out for a tendon problem does not constitute evidence that hair density will increase or that facial appearance will change. The treatment of musculoskeletal conditions is not assessed here.

In hair research, measures such as the number of hairs in a particular area, the thickness of the hair shaft and shedding are examined.^3,4 In skin studies, different outcomes are used, such as appearance assessments, elasticity and the participant's own assessment.⁵ Gathering all of these under a single outcome called "rejuvenation" obscures which change was shown.

An increase in hair density does not mean that every hair shaft has thickened or that the cause of the hair loss has been removed.^3,4 In the same way, a favourable assessment of skin appearance is not a result equivalent to the surgical lifting of facial tissues; the skin review considered here does not show such an equivalence.⁵

Using PRP on its own and adding it to another procedure also have to be separated. In skin research there are studies in which PRP was assessed together with lasers, fat injection or other substances.⁵ The whole result of a combined procedure cannot be attributed to PRP. This page assesses the contribution of PRP; the application detail of skin-resurfacing methods and the evidence for other substances are separate subjects.

What does the evidence on effectiveness show?

Which diagnosis has been studied in hair loss?

Hair loss is not the name of a single disease. The causes and the course of conditions such as androgenetic alopecia, alopecia areata and telogen effluvium differ.⁴ In reading research about PRP, the diagnosis with which the participants were enrolled has to be looked at first. A result found in androgenetic alopecia cannot be carried directly to another type of loss.

The core comparison below is between PRP and placebo in androgenetic alopecia.³ A placebo is a control treatment that does not contain the PRP component being studied. This comparison does not measure the take of grafts in people having a hair transplant, or whether PRP is superior to all medicines.³

In the broader review by Anitua and colleagues, different diagnoses of hair loss were examined, but it is stated that studies of androgenetic alopecia outnumbered those of other diagnoses.⁴ That no significant difference was found between diagnostic subgroups should not be read as proof of the same benefit in every type of loss; the authors particularly emphasise the imbalance of the groups and the limited data.⁴

Does PRP on its own increase hair density?

14 studies with a total of 431 people were included in the systematic review by Kieling and colleagues; 13 studies entered the meta-analysis, that is the quantitative assessment in which results are calculated together.³ In the comparison of PRP with placebo, a mean difference in favour of PRP was reported for hair density.³

Outcome measured	Studies in the meta-analysis	Mean difference	95 per cent confidence interval	I²	Certainty of evidence
Hair density	13	27.55 hairs/cm² increase	14.04-41.06 hairs/cm²	95.99 per cent	Low
Hair shaft thickness	5	2.02 µm increase	-0.85 to 4.88 µm	77.11 per cent	Very low

The two results in the table come from the same review, but were measured by different numbers of studies.³ The density result is the mean difference between PRP and control in the area measured. It is not a success percentage, the number of hairs gained over the whole head, or a fixed amount to be added for every person. Nor does the confidence interval show the least and the most hair participants gained; it shows the uncertainty of the calculated mean difference.

I² is an indicator that assesses how much the results of studies differ from one another. The high value in the density analysis shows that the individual studies did not give an effect of the same size.³ The authors count differences in preparation, study design and follow-up among the factors reducing confidence in the evidence.³ Low certainty does not mean the favourable finding is disregarded; it means that more robust research is needed on the size of the effect.

Alongside studies comparing different people, the review also includes studies comparing different sides of the same person's scalp.³ The number of studies, the number of people and the number of areas compared are therefore not the same unit. The results in the table cannot be added together to calculate a total success or an individual gain.

Are density and shaft thickness the same outcome?

Density describes the hairs counted in a particular area; thickness describes the diameter of the hair shaft.³ Finding a change in one does not show that the other changed to the same extent. The confidence interval reported for thickness includes zero; that result cannot be presented as though a clear superiority of PRP in shaft thickness had been shown.³

Although p=0.02 appears next to the thickness result in the source, the confidence interval for the same result is given as -0.85 to 4.88 µm.³ No definite conclusion of superiority is drawn from that presentation; the confidence interval and the authors' assessment of very low certainty of evidence are preserved together here. This problem between the figures should not be confused with the result of the density measurement.

There are also differing signals in the assessment of publication bias. The authors made an interpretation of publication bias from the asymmetry of the funnel plot, which shows the distribution of results from small and large studies; on the other hand they report that the statistical test known as Egger's test did not identify publication bias.³ It is therefore not appropriate to say that "publication bias has been proven statistically". A concern that findings may have been published selectively and the demonstration of that in a test are not the same thing.

What do comparison with a medicine and added treatment change?

The 2025 review by Anitua and colleagues covers 43 randomised studies and 1,877 participants.⁴ The studies address the use of PRP on its own or added to other treatments, different control groups and different diagnoses of hair loss together.⁴ Favourable results were reported for density, while no significant difference was shown in hair shaft thickness.⁴

This broader set of research is not a repetition of the PRP-versus-placebo comparison under another name. That PRP differs from placebo does not show that it is better than an active medicine. Comparing medical treatment with PRP added against medical treatment alone also does not answer the question of whether PRP can take the place of the medicine. What was done in the groups compared has to be read together with the result.⁴

In the review, no significant difference was found for hair density in comparisons with some active treatments.⁴ That situation is not a result showing that the methods are equivalent in every person or that an existing treatment should be stopped. A study failing to detect a difference and demonstrating equivalence are different research questions.

In the activated PRP subgroup a favourable finding was reported for density, but the interaction test that directly examines the difference between activation groups was not significant.⁴ The superiority of a particular preparation method is therefore not inferred from a favourable result in one subgroup. The authors of the review disclosed their financial relationships with an organisation working on PRP technology.⁴ That information does not on its own invalidate the research; it requires that interpretations turned into recommendations about method be assessed separately.

How does use together with a hair transplant differ?

PRP is not an obligatory complement to a transplant and does not create a new donor area. Studies of density carried out without a hair transplant are not studies measuring whether adding PRP during a transplant is necessary.^3,4 An increase in a measurement of hair density is also not a measurement showing that a new donor area has been created.

The evidence on use together with a transplant is assessed separately in the hair loss treatment article. It explains there how accompanying medical treatment, and the way participants were allocated to groups, limit the results. Those reservations are not removed on the grounds that a broader literature exists examining PRP on its own. The set of research here is not combined with those studies to produce a shared success rate.

What is known about skin appearance?

The 2024 umbrella review by Cruciani and colleagues examined 13 systematic reviews; the 114 overlapping reports in those reviews rest on 28 separate primary studies.⁵ 18 of these are uncontrolled; 20 studies assessed PRP on its own and 8 assessed it together with other treatments.⁵ The number of reports is therefore not the number of independent experiments.

Favourable results were described for participant assessment and some skin measurements in combined treatments.⁵ At the same time, the review states that there is not enough evidence to reach a firm conclusion about the effect on facial appearance of PRP used on its own or added to other procedures.⁵ This does not mean that ineffectiveness has been proven; how large the favourable findings are, and how reliable, has not yet been sufficiently determined.

A favourable assessment of appearance after a combined procedure and PRP producing the same change on its own are separate claims. The absence of a control group, and the assessment of results with subjective scales, can make that distinction harder.⁵ The numerical difference found for hair density also cannot be used as evidence for skin appearance.

How are authorisation and the nature of the product assessed in Türkiye?

Are a certificate and a facility's authorisation the same thing?

How health services for aesthetic and cosmetic purposes are to be provided in private outpatient diagnosis and treatment facilities is governed by the Regulation on Private Health Facilities Providing Outpatient Diagnosis and Treatment, dated 19 April 2025.⁶

The provision in force requires three conditions together. Health services for aesthetic or cosmetic purposes may be provided within a medical centre, a polyclinic or a doctor's practice; within the competences physicians have acquired through their training curriculum or through a certificate; within the medical procedures permitted at the facility where they work; and provided that the physical space and minimum medical equipment defined for a polyclinic room are in place.⁶

The certificate referred to in the regulation is one registered under Ministry legislation.⁶

In the Ministry of Health's Standard for the Certified Training Programme in Aesthetic and Cosmetic Applications, dated 3 September 2025, PRP appears within the "Skin rejuvenation" heading of the theoretical training.⁷ Equipment for preparing PRP is also listed under the same heading.⁷ PRP does not have a separate training heading of its own in the way that fillers and lasers do.⁷ Its presence in the training content should not be read as a separately defined and unlimited authorisation for every diagnosis of hair loss.

The physician's competence and the facility's authorisation are separate things and both are required.⁶ A diploma alone, or any course certificate alone, does not show that all of these conditions are met. Nor is a training centre's authorisation to provide training the same thing as a physician's authorisation to carry out the procedure.^6,7

This provision covers private outpatient diagnosis and treatment facilities. A complete list of authorisation by profession and title, for every type of institution, cannot be derived from this text.⁶

How are a blood product and the device used distinguished?

That a device is used in preparing PRP does not make the blood derivative given back to the person the same thing as that device.¹ Law no. 5624 on Blood and Blood Products expressly counts platelets and plasma among blood components.⁸ The law covers natural and private legal persons authorised by the Ministry to operate in this field, while leaving blood stem cell applications outside its scope.⁸ A blood component and a stem cell application are therefore kept separate in the legal text as well.⁸

The general provisions examined do not on their own clarify the specific route of authorisation for preparing and locally applying autologous PRP for aesthetic purposes.⁸ The product being a blood derivative is therefore not an explanation that takes the place of the physician's competence and the services permitted at the facility.^6,8 The name of the equipment used and the purpose of the procedure performed also have to be understood separately; the presence of a device does not mean that a clinical benefit has been shown for that purpose.

What are the risks and unwanted effects?

Local effects and the handling of the blood

The American Academy of Dermatology (AAD) states that pain, bruising and swelling can occur after PRP.² The Anitua review, which assesses hair research, likewise describes local effects such as pain, discomfort, minor bleeding, bruising and redness.⁴ These are not problems of the same weight as the vision-threatening events described below.

In the same hair review, the proportion of people experiencing at least one side effect did not differ significantly between the PRP and control arms.⁴ At the same time it is stated that most studies did not follow unwanted effects as a main outcome, and that the records are sparse and inconsistent.⁴ That a higher frequency of unwanted effects was reported in the non-activated PRP subgroup does not on its own establish that a particular preparation is safer for everyone.⁴ Incomplete safety reporting should not be read as an absence of risk either.

That the blood belongs to the person does not remove the need to maintain sterility while the blood is taken and processed.² The AAD emphasises both that the blood should be processed in clean conditions and that the preparation should be returned to the correct person.² The explanation "it is your own blood" therefore does not answer the whole question of where and how the procedure is carried out.

A report published by the United States Centers for Disease Control and Prevention (CDC) described presumptive HIV transmission associated with PRP microneedling procedures at a facility with serious breaches of infection control.⁹ The source of the contamination could not be determined.⁹ That event does not show that a person's own blood causes infection by itself, or that the same risk exists in every PRP treatment. It shows a safety problem in the handling of blood; a general PRP infection percentage cannot be calculated from it.⁹

Why are symptoms affecting vision assessed separately?

Cases affecting the blood supply of the eye and leading to permanent vision loss have been reported after PRP injections in the facial region; the source characterises these events as rare.¹⁰ The case review by Ebrahimzade and colleagues examines these serious events; it is not a study following everyone who has had PRP.¹⁰ The cases in the review therefore do not show in what proportion of people having the procedure a vision problem developed.

The outcomes in the case reports are not all the same; there are people in whom improvement in vision was reported, but that does not give an assurance that vision loss can be reversed.¹⁰ Nor can every region of facial and scalp treatment be represented by a single risk figure. The source shows that a serious event can occur; it does not provide a separate frequency calculation for each region.¹⁰

A sudden reduction in vision, loss of vision, or a change in vision together with eye pain during or after the procedure should not be expected in the way ordinary bruising or swelling is, and requires urgent assessment.¹⁰ Waiting for it to resolve with something applied at home is not appropriate. Even where the frequency of the risk is not fully known, the urgency of the symptom is a separate matter.

How is the duration of the result assessed?

Does the follow-up period mean persistence?

When a study made its measurement and how long the change obtained lasted are not the same question. The starting points of follow-up and the times of measurement differ between the studies in the Kieling review; some results were assessed from the first treatment and some after the treatments were completed.³ Combining these times as though they had a shared starting point makes the duration of the effect of PRP appear more certain than it is.

That a difference was found at a study's final assessment does not prove that the difference will remain the same in the period that follows. The Anitua review states that more research is needed on whether long-term benefit continues and on what the duration of the effect is.⁴ The review examined for skin likewise counts differences in preparation, treatment regimen and follow-up periods among the factors limiting the interpretation of the results.⁵

Giving a single interval in months or years for all uses of PRP is therefore not appropriate. When hair density was measured, when skin appearance was assessed, and a person wanting a repeat procedure are different pieces of information. A request for a repeat procedure cannot be used on its own as a measurement showing that the biological effect has ended completely.

In assessing a statement about duration, it has to be understood which outcome is meant, from where the time is counted, and whether other treatments continued in the meantime. The treatment regimens in research are not an instruction given to a person to continue or repeat. No renewal interval is recommended in this article.

What matters in the assessment?

The cause of the hair loss and the medical history

Establishing the diagnosis first matters in hair loss; loss due to different causes is not the same process.⁴ Which diagnosis, what degree of loss and which accompanying treatments featured in the research is part of assessing how far that finding fits a person.^3,4 Saying only "PRP for hair" does not explain these details.

The medical history is also part of the assessment. The AAD states that it does not recommend PRP for skin appearance in cases of hepatitis C, HIV/AIDS, blood cancers, cardiovascular disease requiring a blood thinner, and skin cancer in the area to be treated.² That framework is not given so that a person can judge themselves suitable by looking at a list alone, or stop their medicines. Medicines being used and existing conditions are to be disclosed in the assessment.

Defining the expected change at the outset also matters. A measurable difference in the number of hairs, a reduction in the complaint of shedding, and a person finding their appearance satisfactory are not the same as one another.^3,4 Without knowing which was studied, the phrase "a response was obtained" remains incomplete. An assessment should not begin from the assumption that PRP will be carried out; the aim, the available evidence and the uncertainty are considered together.

How should the marketing language be read?

What do "stem cells" and "your own blood" not prove?

A statement about mechanism such as "it stimulates stem cells" is not the same thing as stem cells being given.¹ In the same way, the presence of growth factors does not show that a change of a particular size in skin or hair is guaranteed. Which clinical outcome the mechanism was tested against has to be stated separately.

"Your own blood" describes the source of the product; it does not on its own explain sterility, return to the correct person, or benefit in every individual.^1,9 No conclusion of freedom from risk should be drawn from the words natural or autologous. Equally, the lack of standardisation should not be used to mean that every treatment is ineffective; what the research supports and what it has not yet been able to determine are read together.¹

Is an "approved kit" a guarantee of results?

Stating the name of a piece of equipment, or a claim of approval, does not answer the question of which research showed a clinical benefit for the hair or skin problem concerned. The presence of PRP equipment in the training standard is likewise not a guarantee of effectiveness in every area of use.⁷ The physician's competence, the services permitted at the facility and the result shown by the research are separate questions.⁶

In information given, the purpose should be understood before the label of a product or method. If a favourable finding is given for hair density, whether the comparison was with placebo or with a medicine should be clear; if a result for skin is given, whether PRP was used on its own or together with another procedure should be clear.^3-5 Saying these details is not recommending the procedure; it makes the claim measurable and open to assessment.

How should the numbers in this article be read?

The value in the hair density table is the pooled estimate of the difference in hair density per cm² between PRP and placebo; it is not a success percentage or a total number of new hair roots.³ The thickness result is a different measure and its confidence interval includes zero.³ A confidence interval and I², which shows how far studies diverge from one another, are also not the same information. One assesses the uncertainty of the estimate, the other the variation between studies.

The studies covered by reviews can overlap with one another; the numbers of people in different reviews are not added together to obtain one large experiment.^3,4 The overlapping reports in the skin review are likewise not counted as independent studies.⁵ The cases of vision loss and the infection investigation are not samples giving a risk percentage for everyone who has the procedure.^9,10

These figures do not determine an individual treatment schedule, a required number of sessions or a promise of results. The meaning of a figure has to be established together with who was studied, what it was compared against, what was measured and when it was assessed.

References

1. Everts P, Onishi K, Jayaram P, et al. Platelet-Rich Plasma: New Performance Understandings and Therapeutic Considerations in 2020. Int J Mol Sci. 2020;21(20):7794. doi:10.3390/ijms21207794 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹

2. American Academy of Dermatology. Is platelet-rich plasma the secret to younger-looking skin? aad.org ↩ ↩² ↩³ ↩⁴ ↩⁵

3. Kieling L, Konzen AT, Zanella RK, et al. Is autologous platelet-rich plasma capable of increasing hair density in patients with androgenic alopecia? A systematic review and meta-analysis of randomized clinical trials. An Bras Dermatol. 2024;99(6):847-862. doi:10.1016/j.abd.2024.01.002 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²²

4. Anitua E, Tierno R, Alkhraisat MH. Platelet-Rich Plasma in the Management of Alopecia: A Systematic Review and Meta-Analysis of Clinical Evidence. Dermatol Ther (Heidelb). 2025;15(11):3213-3252. doi:10.1007/s13555-025-01542-8 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹ ↩¹² ↩¹³ ↩¹⁴ ↩¹⁵ ↩¹⁶ ↩¹⁷ ↩¹⁸ ↩¹⁹ ↩²⁰ ↩²¹ ↩²² ↩²³

5. Cruciani M, Masiello F, Pati I, et al. Platelet rich plasma for facial rejuvenation: an overview of systematic reviews. Blood Transfus. 2024;22(5):429-439. doi:10.2450/BloodTransfus.730 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰ ↩¹¹

6. Republic of Türkiye Ministry of Health. Regulation on Private Health Facilities Providing Outpatient Diagnosis and Treatment. Official Gazette, 19 April 2025, no. 32875. saglik.gov.tr ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸

7. Republic of Türkiye Ministry of Health. Standard for the Certified Training Programme in Aesthetic and Cosmetic Applications. 3 September 2025. saglik.gov.tr ↩ ↩² ↩³ ↩⁴ ↩⁵

8. Republic of Türkiye. Law no. 5624 on Blood and Blood Products. Official Gazette, 2 May 2007, no. 26510. resmigazete.gov.tr ↩ ↩² ↩³ ↩⁴ ↩⁵

9. Stadelman-Behar AM, Gehre MN, Atallah L, et al. Investigation of Presumptive HIV Transmission Associated with Receipt of Platelet-Rich Plasma Microneedling Facials at a Spa Among Former Spa Clients - New Mexico, 2018-2023. MMWR Morb Mortal Wkly Rep. 2024;73(16):372-376. doi:10.15585/mmwr.mm7316a3 ↩ ↩² ↩³ ↩⁴ ↩⁵

10. Ebrahimzade M, Nazari S, Pourani M, et al. Ophthalmic Vascular Occlusion and Blindness After Platelet-Rich Plasma Injections: A Systematic Review. J Cosmet Dermatol. 2026;25(6):e70918. doi:10.1111/jocd.70918 ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶