The Priapus Shot® (P-Shot®) is an autologous platelet-rich plasma (PRP) procedure evaluated for supporting vascular function and tissue health in erectile dysfunction. If you are considering this treatment, you are likely asking: how does the P-Shot work biologically and procedurally?
Unlike oral PDE5 inhibitors that provide temporary situational blood flow for a few hours, the P-Shot is designed to introduce concentrated biological growth factors derived from your own blood into penile tissue. In this guide, we break down the procedure step-by-step, separating proposed biological mechanisms from demonstrated clinical outcomes.
Step 1: The Blood Draw
The procedure begins with a standard, routine blood draw from your arm (approximately 1 to 2 small collection tubes), identical to a regular laboratory test. This sample provides the raw biological material needed to prepare your autologous Platelet-Rich Plasma.
Because the treatment utilizes only your own concentrated blood components, the risk of allergic reaction or biological rejection is minimal. However, as with any needle-based procedure, standard injection risks like mild bruising, tenderness, or temporary swelling remain possible.
Step 2: Centrifugation & Platelet Concentration
Immediately following collection, the tube is processed in a high-precision Eppendorf centrifuge system. The centrifuge spins the sample at controlled speeds and gravitational forces to separate blood components by density:
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Red Blood Cells: Denser cellular components separate to the base of the tube.
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Platelet-Poor Plasma: Clear acellular fluid floats to the top layer.
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Platelet-Rich Plasma (PRP): The concentrated platelet buffy coat containing essential cytokines and bioactive growth factors is meticulously isolated.
This isolated PRP contains a significantly elevated concentration of blood platelets compared to baseline peripheral blood. These platelets contain alpha granules packed with cellular signaling proteins—including VEGF (vascular endothelial growth factor), PDGF (platelet-derived growth factor), and FGF (fibroblast growth factor).
Step 3: Topical Numbing & Patient Comfort
While your sample is being processed, patient comfort is prioritized. A high-potency medical-grade topical anesthetic cream is applied to the penile shaft for approximately 20 to 30 minutes to numb the skin and superficial sensory nerves.
Is the procedure painful?
Most men describe the sensation as mild pressure rather than sharp pain due to the thorough topical anesthesia. While individual sensitivity varies, the injections are performed quickly with ultra-fine gauge needles, and the procedure is generally well tolerated.
Step 4: Targeted Micro-Injections
Once appropriate anesthesia is achieved, the concentrated PRP is activated and carefully delivered via precise micro-injections into specific anatomical zones of the penis—predominantly the paired corpora cavernosa (the erectile chambers that engorge with arterial blood) and the glans.
Accurate anatomical placement by an experienced clinician is vital to ensure growth factors are deposited into the vascular compartments where cellular exchange occurs.
Step 5: Proposed Biological Mechanisms vs. Clinical Realities
Understanding how PRP functions requires distinguishing between hypothesized laboratory mechanisms and clinically observed outcomes:
Microvascular Signaling (Angiogenesis)
In preclinical models, growth factors like VEGF stimulate endothelial cell signaling and microvascular capillary formation. In responsive clinical patients, this may help improve local blood flow and cavernous filling capacity, though responses vary depending on baseline cardiovascular and diabetic health.
Neuro-Sensory Modulation
Platelet-derived signaling molecules have demonstrated neurotrophic properties in research settings. While PRP cannot guarantee nerve regrowth in cases of complete surgical nerve transection, many men report improved tactile sensitivity and sensory responsiveness across the glans following treatment.
Tissue Remodeling Considerations
PRP is studied for its role in cellular extracellular matrix modulation. However, scientific evidence does not show that PRP breaks down calcified plaques or reliably straightens curvature caused by Peyronie's disease; patients with severe curvature require specialized urological evaluation.
Step 6: Aftercare, Recovery, and Timeline
The in-office appointment takes approximately 60 to 80 minutes in total. Because the procedure is non-surgical, recovery time is minimal and you can drive yourself home immediately. Most patients can return to work and light daily activities right away.
Post-Procedure Aftercare: To protect the injection sites, allow initial healing, and reduce the risk of superficial irritation or infection, Dr. Nina Gupta advises refraining from sexual intercourse or vigorous physical activity for at least 24 to 48 hours following treatment.
When to evaluate results: Biological tissue response is gradual. Mild swelling immediately after the injection typically subsides within 2 to 3 days. Early functional changes may emerge between weeks 3 and 6, while peak clinical outcomes are generally evaluated at 8 to 12 weeks during structured medical follow-up. Longevity varies widely—many responding men experience benefits lasting 12 to 18 months, while others may experience modest or limited improvement.