Alprostadil vs Tadalafil
A side-by-side research comparison of Alprostadil and Tadalafil across mechanism, dosing, half-life, benefits, side effects and research status.
Comparison table
| Attribute | Alprostadil | Tadalafil |
|---|---|---|
| Full name | Alprostadil (Prostaglandin E1) | Tadalafil (Cialis) |
| Category | Sexual Health | Sexual Health |
| Status | FDA-approved drug (prescription) | FDA-approved prescription |
| Mechanism | Alprostadil activates prostaglandin receptors that raise intracellular cAMP in cavernosal smooth muscle, causing vasodilation and increased blood inflow to produce an erection regardless of nerve signaling or arousal. | Selectively inhibits phosphodiesterase type 5 (PDE5), preventing cGMP breakdown in smooth muscle. This enhances nitric oxide signaling for vasodilation in penile, pulmonary, and prostate tissue. |
| Molecular weight | 354.5 Da | 389.40 Da |
| Half-life | Very short (minutes, locally metabolized) | ~17.5 hours |
| Bioavailability | Intracavernosal injection or intraurethral suppository | ~36% oral |
| Typical dose | Provider-titrated per response | 2.5-5 mg daily or 10-20 mg as needed |
| Frequency | As needed before activity | Daily or on-demand |
| Route | Intracavernosal injection or urethral pellet | Oral tablet |
Alprostadil reported benefits
- Effective for erectile dysfunction
- Works independent of arousal
- Rapid onset
- Useful when oral PDE5 inhibitors fail
Tadalafil reported benefits
- Erectile function improvement
- Cardiovascular health (vasodilation)
- Prostate health (BPH)
- Improved exercise capacity
- Nitric oxide support
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Research and educational reference only. Not medical advice.