Sildenafil (sold under brands like Vigora 100 mg) should not be taken twice a day. Recommended dosing Usual dose: 50 mg or 100 mg as needed Maximum frequency: once in 24 hours Taken about 30–60 minutes before ***** activity Why twice a day is not safe Taking Vigora 100 mg more than once in a day can significantly increase the risk of side effects because the drug already stays active in the body for several hours. Re-dosing too soon can lead to: Low blood pressure (hypotension) Severe headache or dizziness Flushing and rapid heartbeat Vision disturbances (blurred or blue-tinted vision) Painful or prolonged erection (priapism) — a medical emergency Important point Even if the effect feels weaker after one dose, it does not mean you should take another tablet the same day. The body is still processing the first dose. Safer approach Stick to one tablet per day maximum Avoid alcohol or heavy fatty meals before taking it (they can reduce effectiveness) If 100 mg feels too strong or causes side effects, a doctor may adjust you to 25 mg or 50 mg Bottom line Vigora 100 mg is designed for single-use, once-daily maximum dosing—not twice a day under any circumstance unless specifically directed by a doctor.