Understanding Viagra's Mechanism of Action
The Science Behind Viagra
Viagra contains sildenafil citrate, which belongs to a class of medications called PDE5 inhibitors. When you're sexually aroused, your body naturally produces nitric oxide, which triggers the production of cyclic GMP. This chemical helps relax smooth muscle tissues in blood vessels, allowing increased blood flow to the penis. However, the PDE5 enzyme breaks down cyclic GMP, reducing blood flow. Viagra works by blocking this PDE5 enzyme, maintaining higher levels of cyclic GMP and supporting improved blood flow when sexually stimulated.
Timeline and Duration
Most men find that Viagra begins working within 30-60 minutes of taking the tablet. The medication doesn't cause automatic erections - sexual stimulation is still required for it to be effective. Effects may last up to 4-6 hours, though this doesn't mean you'll have an erection for this entire period. The duration can vary based on factors including age, overall health, dosage, and whether you've eaten recently. Fatty meals can delay the onset of action, so consider taking Viagra on a relatively empty stomach for optimal results.
Dosage and Administration
Viagra is available in 25mg, 50mg, and 100mg strengths, with 50mg being the typical starting dose. Your prescriber may adjust this based on how well it works for you and any side effects you experience. It's crucial to take only one dose within any 24-hour period, approximately 30-60 minutes before sexual activity. At EverydayMeds, patients can choose between branded Viagra and generic sildenafil - both contain the same active ingredient and work identically, with sildenafil often being the more cost-effective option.
Who Can Take Viagra
Viagra requires a prescription following consultation with a UK-licensed prescriber. It's suitable for adult men experiencing erectile dysfunction, but isn't appropriate for everyone. During your clinical assessment, the prescriber will evaluate your cardiovascular health, current medications, and medical history. Viagra cannot be taken alongside nitrate medications (such as GTN spray), and it's not suitable for men with severe heart conditions, recent stroke or heart attack, severe liver problems, or very low blood pressure. Your safety is paramount, which is why a thorough medical assessment is essential before starting treatment.
