Viagra

How It Works

The medicine inhibits PDE5, the enzyme that breaks down cyclic GMP in erectile tissue. During sexual stimulation, nitric oxide increases cyclic GMP and relaxes smooth muscle, allowing more blood to enter the penis. The medicine prolongs that signal and improves the erectile response.

Erectile Firmness and Sexual Performance

Sildenafil improves the ability to achieve and maintain an erection in men with erectile dysfunction. Its action depends on sexual stimulation and blood flow signalling. The established benefit is erectile function; a direct increase in testosterone or muscle growth is not established.

• Increasing the erectile response to sexual stimulation.
• Improving erection firmness and maintenance.
• Prolonging nitric oxide dependent cyclic GMP signalling.

Post Cycle Therapy

The medicine does not require PCT and does not restart suppressed testosterone production. It can improve erections while a separate hormonal problem remains present. Recovery after anabolic steroid exposure is determined by the hormonal axis rather than the erectile response to treatment.

Side Effects

Common effects include headache, flushing, nasal congestion, indigestion and visual colour changes. Blood pressure can fall, and rare serious risks include prolonged erection and sudden vision or hearing loss. Combining sildenafil with nitrates or recreational nitrite poppers can cause dangerous hypotension. Other blood pressure lowering medicines can also interact.