PRP in aesthetics: the biologic nobody questions

The biologic nobody questions

Picture two procedures on the same afternoon. In the first, a researcher reconstitutes a peptide of known sequence, with HPLC-measured purity and a lot-specific certificate of analysis. In the second, the patient's blood is drawn, spun in the office, and the plasma is injected into the scalp or face. Which of the two draws more questions at a dermatology meeting? Almost always the first.

This article does not attack PRP. It has real data, and in one indication those data are better than those of many aesthetic treatments. What it proposes is to look at both through the same lens. The context of regenerative aesthetics in the US is in what is offered in New York and Beverly Hills, and the same argument applied to stem cells is in the double standard.

What PRP is, and why there is no single PRP

PRP is autologous plasma with a platelet concentration above baseline blood. The problem starts with the definition. As early as 2009, platelet concentrates were divided into four families by leukocyte and fibrin content: pure PRP, leukocyte-rich PRP, pure platelet-rich fibrin (P-PRF) and leukocyte- and platelet-rich fibrin (L-PRF); each method yields a product with different biology¹. In 2012, the PAW classification added three variables, absolute platelet number, mode of activation and presence of white cells, because protocols "vary widely" and are often not documented, which makes results hard to compare or replicate².

The DEPA classification quantified it. Applied to 20 preparations with published data, the injected platelet dose ranged from 0.21 to 5.43 billion, a 25-fold range; no device recovered more than 90% of platelets, and only three achieved the top purity score, because most carried red blood cells³. In the aesthetic literature, a review of 22 studies on face, acne scars and alopecia found significant variation in preparation and in the number and frequency of sessions⁴.

Androgenetic alopecia: the indication with the best data

Here PRP has randomized trials. A 2024 meta-analysis included 14 studies with 431 patients (13 in the quantitative analysis) and found a mean difference of 27.55 hairs/cm² versus placebo (95% CI 14.04 to 41.06), with no significant difference in hair diameter⁵. The authors themselves note very high heterogeneity (I² = 95.99%), low-quality studies and evident publication bias⁵. In women, 21 trials with 628 participants showed greater hair density and thickness, with mild, transient adverse effects⁶.

Against the standard of care the result is more modest. Nine trials with 451 participants showed no significant difference in hair density between PRP and topical minoxidil; satisfaction was higher with PRP (OR 2.77) and a negative pull test more frequent (82.75% vs 52.94%), but terminal hair count was similar⁷. The peptides competing in this space are reviewed in peptides and hair loss.

Face, scars, melasma and dark circles

Facial rejuvenation. An umbrella review of 13 systematic reviews found only 28 primary studies, 18 of them uncontrolled; confidence was low or critically low in 12 of the 13, and the authors concluded the evidence is insufficient for firm conclusions⁸. Another review, of 36 studies with 3,172 patients, rated the clinical evidence as very limited⁹.

Acne scars. This is the strongest facial indication, always as an adjunct. Eleven randomized trials with 313 participants compared ablative fractional CO2 laser with and without PRP: the combination was associated with more clinical improvement (OR 2.56) and more satisfaction (OR 3.38)¹⁰. An earlier meta-analysis of 7 studies, with fractional laser or microneedling as the main therapy, found an OR of 8.19 for improvement, with substantial heterogeneity¹¹.

Melasma. A 2021 meta-analysis (10 studies, 395 patients) showed a 1.18-point reduction in mMASI before versus after treatment¹². But the 2026 analysis, with 11 studies and a comparator group, found no significant difference versus other treatments, even in combination, and its result hinged on a single small study¹³.

Dark circles. A systematic review of 39 studies on periorbital hyperpigmentation listed PRP among options with favorable results, but warned that the scarcity of high-quality evidence means recommendations should be interpreted selectively¹⁴.

Regulation: the centrifuge is cleared, not the treatment

In the US, blood and its components fall outside the definition of HCT/Ps: the rule expressly excludes "Whole blood or blood components or blood derivative products subject to listing under parts 607 and 207"¹⁶. That is why PRP does not follow the traditional pathway of animal studies and clinical trials¹⁵.

What reaches the market through the 510(k) pathway, by "substantial equivalence", is the preparation system, and nearly all such systems are cleared to produce a concentrate mixed with bone graft in orthopedic surgery; an office injection is considered off-label use¹⁵. According to CBER, as quoted in that review, the physician then has "the responsibility to be well informed about the product, to base its use on firm scientific rationale and on sound medical evidence, and to maintain records of the product's use and effects"¹⁵.

Safety: the New Mexico vampire facial

The blood being the patient's own does not remove the risk; it moves it to the process. In 2018, the New Mexico Department of Health and the CDC investigated an unlicensed spa offering PRP with microneedling, the so-called vampire facial¹⁷. They identified 59 exposed clients, 20 of whom received PRP, and between 2018 and 2023 confirmed by sequencing a cluster of 5 HIV cases; investigators considered transmission at the spa likely for 3 patients¹⁷.

The inspection found a centrifuge on the kitchen counter, unlabeled tubes of blood in the refrigerator alongside food, and no autoclave¹⁷. The report notes that HIV transmission through cosmetic injection services via contaminated blood had not been previously documented¹⁷. It is an infection-control failure, not a failure of PRP as a substance; but it is a risk that arises from handling blood, and no lyophilized vial carries it.

One yardstick

A peptide is a defined molecule: known sequence, verifiable mass, a dose expressed in milligrams and a certificate of analysis stating, lot by lot, what is in the vial. PRP has no sequence, its dose can vary 25-fold depending on the device³, there is no certificate for the product being injected, and its clearance covers a centrifuge designed for bone grafts¹⁵. Even so, PRP enters the practice without anyone asking about its purity.

The conclusion is not that PRP should go. It is that the right question, for both, is the same: what exactly is in it, how much is given and what evidence supports it. For PRP, the reviewers themselves call for standardized protocols⁴⁷. For the peptide, much of that standardization already exists in the laboratory.