OnePin Peptide Library · Hormonal
Alprostadil
Caverject · PGE1 · Prostaglandin E1
Alprostadil is the synthetic form of prostaglandin E1 (PGE1), a potent vasodilator. It is FDA-approved in multiple formulations: Caverject and Edex (intracavernosal injection for erectile dysfunction), Muse (urethral suppository for ED), and IV Alprostadil/Prostin VR Pediatric (for maintaining patent ductus arteriosus in neonates with congenital heart disease awaiting surgery). Alprostadil-cream formulations (Vitaros) are also approved in some jurisdictions for ED.
Pre-intercourse for ED. Specific clinical setting for neonatal use. Per FDA label for each formulation.
Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.
How it works
Alprostadil is synthetic prostaglandin E1, a potent endogenous vasodilator and platelet aggregation inhibitor:
EP Receptor Activation
PGE1 binds EP1, EP2, EP3, and EP4 receptors on vascular smooth muscle and other tissues. EP2/EP4 activation increases cAMP, producing smooth muscle relaxation and vasodilation. EP1/EP3 have more complex effects on platelets and inflammatory responses.
Corporal Smooth Muscle Relaxation
In the penis, intracavernosal alprostadil produces direct corporal smooth muscle relaxation via cAMP elevation, allowing arterial inflow and venous outflow restriction - producing an erection independent of neural/psychological arousal pathways. This makes it effective even in vascular and neurogenic ED.
Onset and Duration
Erection within 5-15 minutes of intracavernosal injection; lasts 30-90 minutes. Predictable kinetics with proper dose titration.
Pulmonary First-Pass
PGE1 is rapidly cleared by pulmonary endothelial enzymatic degradation (15-deoxy-PGE1 metabolite formation). Plasma half-life ~30-60 seconds. This makes systemic IV use possible only in specific contexts (neonatal ductus arteriosus) where continuous infusion compensates for rapid clearance.
Priapism Risk
Excessive dose or post-treatment intracavernosal alprostadil retention can produce prolonged erection (>4 hours = priapism, urological emergency). Requires careful dose titration and patient education.
What to expect
Acute erection within 5-15 minutes of intracavernosal dose.
Erection 30-90 minutes per dose.
Repeated use generally well-tolerated; long-term fibrotic plaque risk in some patients.
Evidence
Interactions & stacking
What's safe to combine, and what belongs in a separate pin.
Keep separate
Side effects & safety
Commonly reported
- Penile pain (burning sensation, common)
- Injection site bruising / hematoma
- Mild penile fibrosis with repeated use
- Prolonged erection (1-4 hours, manageable)
Less common & notes
- Priapism (>4 hours, urological emergency requiring aspiration or surgical intervention).
- Penile fibrosis or Peyronie-like plaques with chronic use.
- Vasovagal syncope post-injection (rare).
- Hypotension (rare with intracavernosal due to local action).
- Allergic reactions rare.
- Neonatal IV use has well-characterized respiratory depression risk - clinical setting only.
Pharmacokinetics
Storage. Caverject pen: refrigerate per label. Reconstituted use within 24 hours. Vitaros cream: refrigerate per label.
Regulatory status
FDA-approved across multiple formulations. Prescription-only. Urology-prescribed for ED indication. Pediatric cardiology-prescribed for ductus arteriosus patency. Generic alprostadil also available.
Put it to work
Calculate, log & track
Open Alprostadil straight into OnePin with your vial and dose pre-filled, then let it handle the syringe math and remind you before the vial runs out.
Open Alprostadil in the app →Go deeper
The guide & community
The complete Alprostadil walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.
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