Avanafil is usually purchased at a regular local hospital or pharmacy with a doctor’s prescription. Avanafil is a prescription drug. It is generally used clinically to treat erectile dysfunction in men. For patients with erectile dysfunction, this medication is used following a doctor’s prescription after the cause of the condition has been clarified by the doctor. As long as it is purchased from a regular medical institution, it is usually genuine. A small percentage of people will cause headache, nasopharyngitis, flushing and back and muscle pain while taking the drug. Rarely, upper respiratory tract infections, bronchitis, sinusitis, high blood pressure, dyspnea, nausea, constipation, skin rashes and other symptoms. It should be noted that patients who are allergic to this drug are prohibited from consuming it. It should not be consumed by patients who are taking nitrates, and it is also contraindicated in women, in patients with severe hepatic or renal insufficiency, and in patients who are using guanylate cyclase stimulators. Avanafil needs to be taken carefully with a doctor’s prescription. The patient’s symptoms may be reduced before the disease is fully controlled, but do not easily reduce the dosage or stop the drug, in order to avoid the formation of drug resistance, recurrence or re-exacerbation of the disease, the specific use of the drug need to be under the guidance of a doctor, do not take on their own.