Both vardenafil and sildenafil belong to phosphodiesterase inhibitor type 5, which are mostly used to treat erectile dysfunction in men in the clinic. Due to the severity of the patient’s condition, the sensitivity to the drug and the dose of the drug used are different, so there is no saying which one is better. 1. vardenafil: oral absorption is relatively rapid, the fasting state can reach the maximum blood concentration in as little as 15 minutes, the average peak in about 60 minutes, the clearance half-life is about 4 hours. 2. Sildenafil: the onset of action after oral administration is also relatively fast, the onset of action in 10-40 minutes after taking, the peak can be reached in 30-120 minutes, the half-life of clearance is also about 4 hours. 3. Adverse reactions and contraindications: (1) The main adverse reactions of vardenafil are mild headache, facial flushing, dyspepsia, vertigo, and nausea, etc. It is contraindicated in those who are allergic to the drug components, and in patients who are also taking nitrates, nitrous oxide donors, and HIV protein kinase inhibitors. (2) Sildenafil adverse reactions are more common, common headache, flushing, dyspepsia, vision abnormalities, nasal congestion, back pain, nausea, dizziness, etc., is prohibited in patients who are allergic to any of the components of the drug, taking any dosage form of nitrate drugs. Both have faster onset of action, similar side effects and contraindications, and different patient conditions, so you can’t simply compare which one is better, it is recommended that patients go to the hospital and use it under the guidance of a professional physician.