Last reviewed 2026-04-23 · How we verify

Sublingual sildenafil

Sublingual sildenafil works by increasing blood flow to the penis to treat erectile dysfunction.

Sublingual sildenafil works by increasing blood flow to the penis to treat erectile dysfunction. Used for Erectile dysfunction.

At a glance

Mechanism of action

Sildenafil is a phosphodiesterase type 5 inhibitor that blocks the action of phosphodiesterase type 5, an enzyme that breaks down cyclic guanosine monophosphate (cGMP) in the smooth muscle cells lining blood vessels. This leads to increased levels of cGMP, causing smooth muscle relaxation and increased blood flow to the penis.

Approved indications

• Erectile dysfunction

Common side effects

• Headache
• Flushing
• Dizziness
• Nausea
• Back pain

Key clinical trials

• Pharmacoscintigraphic Study to Evaluate Two Sildenafil Products (PHASE1)
• A Pivotal Study of the Bioequivalence of Oral Viagra® and a Test Sublingual Sildenafil Wafer (PHASE3)
• Study to Evaluate Hemodynamic Response to to a Sublingual Dose of Glyceryl Trinitrate in Subjects Receiving TA-1790, Sildenafil Citrate, and Placebo (PHASE1)
• A Study to Evaluate a Possible Superiority Expressed by the Faster Onset of Action and the Efficacy and Safety of Sildenafil Citrate 20mg Sublingual Tablet in the Treatment of Erectile Dysfunction of Different Etiologies (PHASE3)
• Blood Pressure Interaction Between Sildenafil and Sublingual Glyceryl Trinitrate (GTN) in Men With Angina (PHASE4)

Primary sources

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Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Sublingual sildenafil CI brief — competitive landscape report
• Sublingual sildenafil updates RSS · CI watch RSS
• N4 Pharma UK Ltd. portfolio CI