Zenegra 50 mg, like Kamagra, contains Sildenafil Citrate, which is a PDE5 inhibitor. Nasal congestion (a stuffy or blocked nose) can occur as a side effect because Sildenafil affects blood vessels throughout the body, not just in the *****. Here’s how it happens and when it is most likely to occur: Timing: Nasal congestion usually appears 30 minutes to 1 hour after taking Zenegra, which is around the time the medication starts to work. It may persist for several hours (often 4–6 hours), corresponding to the duration of the drug’s effect. Mechanism: Sildenafil causes vasodilation (widening of blood vessels). This can increase blood flow to the nasal passages, leading to swelling of nasal tissues and a feeling of congestion. Who is more likely to experience it: People prone to allergies or nasal inflammation. Those taking higher doses or combining the medication with other vasodilators. Management: Usually mild and temporary; nasal sprays or antihistamines can help. If severe or persistent, consult a doctor. If you want, I can make a timeline showing exactly when nasal congestion and other side effects usually start and peak after taking Zenegra 50 mg—it’s quite handy for planning doses.