Platelet-Rich Plasma / the 'P-Shot'
PRP Intracavernosal Injection & the Trademarked Priapus Shot, One Small RCT, Orthopedic Kits, and 'Bigger' Marketing
Evidence grade 2 of 5, Thin. Read how the Atlas grades evidence.
The written rationale for this grade is still being prepared.
- FDA
- PRP kits cleared for orthopedic use only; no FDA approval for ED
Reference only. Not medical advice.
What can go wrong
Because PRP is autologous, immunologic risk is low; typical adverse effects are injection-site pain, bruising, and small hematoma, with rare infection. The real issues are cost for an experimental therapy, wide variability in how PRP is prepared (platelet concentration is not standardized), and marketing that promises size gains and sensitivity improvements with no controlled support.
This is something to take to a clinician. The Atlas can tell you what is known about platelet-rich plasma / the 'p-shot' in general. It cannot tell you what is happening in your body, and the difference matters most for exactly the symptoms that bring people to this page.
Platelet-rich plasma (PRP) is a concentrate of the patient's own platelets, prepared by centrifuging their blood and injected into the corpora cavernosa on the theory that the platelet-derived growth factors (PDGF, VEGF, TGF-beta) promote angiogenesis and tissue repair. The best human evidence is a single small double-blind, placebo-controlled RCT: Poulios et al. 2021 (J Sex Med 2021;18(5):926-935), which randomized 60 men with mild-to-moderate ED to two PRP or placebo injections and reported improved erectile-function scores in the PRP arm at follow-up. The commercial version is the trademarked 'P-Shot' / Priapus Shot, created by Charles Runels, MD, who registered the marks and licenses them to providers for a monthly fee. PRP kits themselves are FDA-cleared for orthopedic soft-tissue use, not for ED. The AUA calls PRP experimental. Enlargement and 'bigger' claims are marketing, not trial findings.
One 60-man trial props up a nationwide trademarked injection business.
What people take it for
These are the reasons people give for taking it. They are not effects it has been shown to have.
How it is supposed to work
PRP is prepared by drawing the patient's blood and centrifuging it to concentrate platelets. Injected into the penis, the platelets are hypothesized to release growth factors (platelet-derived growth factor, VEGF, transforming growth factor-beta, epidermal growth factor) that recruit stem cells, stimulate angiogenesis, and promote endothelial and nerve repair. The mechanism is plausible from wound-healing biology but is largely extrapolated; direct evidence of cavernosal regeneration in humans is minimal.
The catch: one small trial, a licensed trademark, and off-label kits
The entire clinical case rests essentially on the Poulios 2021 RCT (n=60) plus small uncontrolled series; systematic reviews caution that the evidence base is thin and heterogeneous. The commercial layer is a trademark: Charles Runels registered 'Priapus Shot' and 'P-Shot' and licenses the names (a monthly per-provider fee via the Cellular Medicine Association), so much of what looks like a treatment is actually a branding and directory business. The PRP-preparation kits are 510(k)-cleared for orthopedic/soft-tissue use; using them for ED is off-label, and there is no PRP product approved for erectile dysfunction.
What people get wrong
Often saidThe P-Shot is FDA-approved
ActuallyIt is not. PRP kits are cleared for orthopedic use; the AUA classifies PRP for ED as experimental.
Often saidPRP makes the penis bigger
ActuallyNo controlled trial shows any increase in length or girth. 'Bigger' is a marketing claim tied to the trademark's own description, not to data.
Often saidThe 'P-Shot' is a distinct proven procedure
ActuallyIt is a trademarked brand name for PRP injection; the licensing fee buys the name and directory listing, not additional evidence.
Who profits, and who pushes back
AUA ED Guideline Panel
PRP therapy for ED should be considered experimental.
ISSM
Evidence for PRP in ED is limited; it should be regarded as investigational.
Money flows to the trademark licensor (recurring per-provider fees), the kit and centrifuge manufacturers, and the clinics charging four-figure cash prices per injection. The branding is itself a revenue stream layered on top of a low-cost blood-processing procedure.
What we do not know
- Can the Poulios result be replicated in larger, multicenter trials?
- Does the lack of PRP standardization (platelet concentration, activation) explain inconsistent real-world results?
- Is any benefit durable, or does it fade like the shockwave response?
At a glance
- Key RCT
- Poulios 2021, J Sex Med, n=60
- Kit FDA status
- Cleared for orthopedics, not ED
- Trademark
- P-Shot / Priapus Shot (Charles Runels, MD)
- AUA 2018
- Experimental
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about Platelet-Rich Plasma / the 'P-Shot'. A short entry is not a safe entry.
- Timeline. We have not built the dated record of research and regulatory events.
- Cost and market. We have not documented what it sells for or who sells it.
- Supply chain. We have not mapped where it is made.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- How it compares. We have not set it against the alternatives.
- Children and teenagers. We have not checked what is known about younger people.
- Where we land. We have not taken a position on this yet.
Sources
The studies below are named and described, but not linked. You cannot open them from here and check our reading against them, which means this page is our summary of the literature rather than a document you can verify. Weigh it accordingly until the links exist.
The studies that matter
Poulios et al., J Sex Med (double-blind, placebo-controlled PRP RCT)2021
n=60; two intracavernosal PRP vs placebo injections; improvement in erectile-function scores in the PRP arm over 6 months, the highest-quality PRP-for-ED trial to date but small