Sildenafil 100mg (commonly known as Viagra) is a medication used to treat erectile dysfunction (ED) in men. Sildenafil works by inhibiting the enzyme phosphodiesterase type 5 (PDE5), which allows blood vessels in the penis to relax and expand, improving blood flow. This helps men achieve and maintain an erection when sexually stimulated. Sildenafil is fast-acting and can provide relief within 30 minutes of ingestion, with effects lasting up to 4-6 hours. Sildenafil is effective in treating ED caused by various factors, including psychological stress, physical health conditions, and age-related decline in sexual function. It should be taken as prescribed, typically on an as-needed basis. Common side effects include headaches, facial flushing, and indigestion. It is important not to take Sildenafil if you are also taking nitrates for chest pain, as this can lead to a dangerous drop in blood pressure. Sildenafil is one of the most widely prescribed medications for ED and is often used by men seeking to restore their sexual confidence and performance.