Viagra is the trade name, generically known as sildenafil citrate tablets, and is not recommended for normal human use. In addition to the possible adverse effects such as headache, dizziness, and nausea that may occur with normal human use, it may also lead to adverse consequences such as persistent penile erection. Sildenafil Citrate Tablets, a prescription medication used to treat erectile dysfunction in men, is not recommended for normal people. Normal people may also experience adverse effects after using sildenafil such as dizziness, headache, nausea and blurred vision. A small percentage of the population may experience adverse reactions such as severe hypotension, sudden loss of vision, and persistent penile erection after using the drug. Sildenafil belongs to the prescription drugs, need to be used under the guidance of a doctor, the normal population is not recommended to use, if there are adverse reactions need to go to the hospital in time for targeted treatment.