Filitra 20 mg contains vardenafil, a PDE5 inhibitor similar to sildenafil (Viagra) and tadalafil (Tadalafil/Tadalista), used to treat erectile dysfunction (ED). After oral intake, Filitra 20 mg usually starts working within 30–60 minutes, though the exact time can vary depending on factors like food intake, metabolism, and overall health. Taking it on an empty stomach often leads to faster absorption, while a heavy or fatty meal may delay its effect. The medication works by inhibiting the PDE5 enzyme, which increases cGMP levels in the penile tissue during sexual stimulation. This relaxes blood vessels and improves blood flow, enabling stronger and longer-lasting erections. Sexual arousal is still necessary; it does not cause an automatic erection. The effects of Filitra 20 mg generally last 4–6 hours, providing a window for sexual activity. Side effects can include headache, flushing, nasal congestion, dizziness, or indigestion, and it should not be used with nitrates or certain heart medications due to potential risks. In short, Filitra 20 mg typically acts within half an hour to an hour, and its effectiveness depends on timing, sexual stimulation, and individual factors.