Biohacking Kompakt

Treatment & Procedure

PRP (Platelet-Rich Plasma)

Biohacking

PRP, platelet-rich plasma, is your own blood in concentrated form: blood is drawn, centrifuged and the platelet concentrate injected back, into the knee, at the tendon or into the scalp. The idea behind it is biologically real, and the procedure is well tolerated. How well it works depends heavily on where it is used, and for the knee the answer is sobering.

In short

PRP uses growth factors from your own platelets, which call repair cells to an injury. For hair, a meta-analysis of 43 randomized trials with 1,877 participants shows greater hair density and less hair loss, with moderate evidence. For tennis elbow, PRP is better than cortisone in the long term, but in 6 randomized trials not better than saline. For knee osteoarthritis, the largest blinded trial with 288 participants found no difference from saline after 12 months, either in pain or in cartilage. The procedure is well tolerated; the real risk lies in poor hygiene during preparation.

What PRP is

For PRP, blood is drawn from you and separated in a centrifuge. The plasma with the concentrated platelets is separated off and injected by the physician at the desired site, for example into the knee joint, at an irritated tendon or into the scalp. In Germany the procedure is also known as Eigenbluttherapie (autologous blood therapy). There are many variants, with more or fewer white blood cells, activated or not activated, and the preparation is nowhere standardized.

PRP is used in orthopedics and sports medicine for osteoarthritis and tendon problems, in dermatology for hair loss and in aesthetics, where it is known as the vampire facelift. Because the material comes from one’s own body, many patients perceive it as natural and gentle.

How it is supposed to work

Platelets are not only there for clotting. They carry growth factors that attract repair cells after an injury and kick-start healing. If you amplify this call and place it directly at the problem site, so the idea goes, you should trigger more repair. This mechanism can be observed with every cut; it is real.

But a mechanism is not yet a result. Whether concentrated growth factors in a worn knee or at a chronically irritated tendon actually achieve more than the natural course has to be tested against a sham treatment. An injection into the joint is one of the most effective sham treatments known to medicine, because the procedure itself and the expectation already relieve symptoms.

What patients report

Orthopedic practices and patients report many cases of clear improvement; they are the reason PRP is so widespread. This improvement is real. The only question is whether it comes from the patient’s own blood: in the large blinded knee trial, the saline group did practically just as well. Experience reports show that people feel better after the treatment, not why.

Anyone who is offered PRP can put the offer into perspective with two questions. First: was it tested against saline for exactly this joint or exactly this complaint, and with what result? The fact that your own blood contains growth factors does not answer this question. Second: who prepares the blood, and under what hygienic conditions? For hair loss, the answer to the first question is considerably more favorable than for the knee.

What is well supported

The picture looks best for hair loss. A 2025 meta-analysis of 43 randomized trials with 1,877 participants found greater hair density and less hair loss with PRP, but not thicker hair, and rates the evidence as moderate. For tennis elbow, a meta-analysis of 26 randomized trials shows that cortisone relieves better in the first weeks, but PRP is ahead in pain and function after more than 6 months. Tolerability is also well supported: in 32 randomized trials with 1,268 treated knees, side effects occurred in 18.7 percent, almost always mild pain and swelling; no serious events were reported.

What the studies show

RESTORE, JAMA 2021

Bennell and colleagues in Australia randomized 288 people aged 50 and over with mild to moderate osteoarthritis on the inner side of the knee, grade 2 or 3 on X-ray. They received 3 injections one week apart, either leukocyte-poor PRP from a commercial product or saline, blinded for participants, injectors and assessors. After 12 months, pain on a scale of 0 to 10 fell by 2.1 versus 1.8 points; the difference of 0.4 points was not significant and lay far below the predefined noticeable threshold of 1.8 points. Cartilage volume decreased equally in both groups, by 1.4 and 1.2 percent. Of 31 predefined secondary questions, 29 showed no difference. 269 participants completed the trial, and 97 percent received all 3 injections.

Tennis elbow versus placebo and versus cortisone

A 2026 meta-analysis pooled 6 randomized trials with 355 patients that compared PRP with a sham treatment. At no time point between 4 and 26 weeks was there a difference in pain or function. Another meta-analysis of 26 randomized trials compared PRP with cortisone: cortisone helped better in the first 2 months, and after more than 6 months PRP was ahead. Taken together, this means: better than cortisone, which does a tendon no good in the long run, but not demonstrably better than saline.

Where the data stop

For the knee, the question has been well studied and turns out negative as soon as blinding is done properly. RESTORE is the largest trial of its kind; it had very few dropouts and two clearly defined primary questions, both of which showed no difference. Small studies had often found benefits before; the large one did not. One objection remains justified: one product, one protocol and one indication were tested. Anyone who believes a different preparation works better would have to show this in an equally rigorous trial.

For tendon and scalp, the question is open, not settled. For tennis elbow, the advantage over saline is missing, and a 2014 Cochrane review on soft tissue injuries found no clinically relevant benefits across 19 small studies, with very low quality of evidence. For hair, the studies are designed very differently and preparation varies widely; the authors call for standardized trials. For the vampire facelift of the skin, there are no comparably reliable data.

Status, approval and legal

In Germany, PRP is a medical service; statutory health insurers do not pay for it in osteoarthritis, and it is offered as a self-pay health service (IGeL). German practices quote very different prices; publicly one finds a good 100 to over 600 euros per session, with 3 sessions being usual. The German Society for Orthopaedics and Orthopaedic Surgery currently does not recommend PRP injections for knee osteoarthritis, and the international osteoarthritis society OARSI and the American rheumatologists even advise against them in their guidelines. The health portal of the IQWiG states that it has not yet been demonstrated that autologous blood therapy can relieve the symptoms of knee osteoarthritis.

Safety

The preparation itself is well tolerated. In the analysis of 32 randomized trials, mild, transient knee pain and swelling were the most common side effects, especially with leukocyte-rich PRP; leukocyte-poor PRP behaved like hyaluronic acid. No serious side effects were reported in any group. The real risk lies in the processing: in 2024 the US health authority CDC documented a total of 5 HIV infections linked to PRP microneedling treatments at an unlicensed cosmetic spa in New Mexico, with unlabeled blood tubes on the kitchen counter, syringes lying around in the open and no sterilizer. 198 former clients and partners were followed up. An injection into the joint is a medical procedure; it belongs in a physician’s practice with proper hygiene.

BK-Score Studied – no benefit shown

Human evidence5
Mechanism4
Safety data6
Hype gap3
Track record of use7

Well studied and predominantly negative as soon as blinding is done properly: the RESTORE trial (JAMA 2021, n=288, twelve months) found no difference from saline in either pain or cartilage volume, and 29 of 31 secondary endpoints showed no difference. For tennis elbow, PRP was not better than placebo in 6 randomized trials, but better than cortisone in the long term; a Cochrane review on soft tissue injuries found no clinically relevant benefits. For hair density there are positive studies with moderate evidence. Additional risk lies in the processing, not in the product: in 2024 the US health authority documented HIV transmissions after non-sterile cosmetic use. The German orthopedic society currently does not recommend PRP for knee osteoarthritis.

The score rates the state of knowledge, not the substance. “Safety data 9” means well studied – not harmless.
Subjective assessment by Biohacking Kompakt based on published scoring rules – not a scientific rating and not a medical recommendation. Rules and all ratings (German)

Frequently asked questions about PRP (platelet-rich plasma)

Does PRP help with knee osteoarthritis?

The largest blinded trial with 288 participants found no difference from saline after 12 months, either in pain or in cartilage. Many patients feel better after the injection, but the saline group did just as well. The German specialist society currently does not recommend PRP for knee osteoarthritis.

Does PRP help against hair loss?

This is where the evidence is most favorable. A meta-analysis of 43 randomized trials found greater hair density and less hair loss, but not thicker hair, and calls the evidence moderate. The studies are designed very differently.

Does PRP help with tennis elbow?

Compared with cortisone, PRP does better in the long term, after more than 6 months. Compared with a sham treatment with saline, 6 randomized trials showed no advantage. The question therefore remains open.

How much does a PRP treatment cost?

German practices quote very different prices; publicly one finds a good 100 to over 600 euros per session. 3 sessions are usual. Statutory health insurers do not pay for PRP in osteoarthritis.

Is PRP dangerous?

The preparation is well tolerated; usually only mild, transient pain and swelling occur. The risk lies in hygiene: HIV transmissions occurred at an unlicensed US cosmetic spa. The treatment belongs in a physician’s practice.

How does a PRP treatment work?

First, blood is drawn and separated in a centrifuge. The plasma with the concentrated platelets is then injected at the desired site, for example into the knee, at a tendon or into the scalp. In the large knee trial there were 3 injections one week apart.

Related

Sources

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Information only, not medical advice and not a usage or dosage recommendation. Prescription-only and unapproved substances belong in the hands of a physician. Last updated: 2026-09-26.