Viagra is the trade name and generic name for sildenafil citrate tablets, the state after taking and ejaculating varies from person to person and usually weakens gradually. Sildenafil is a commonly used drug to treat erectile dysfunction in men. NO plays a key role in the physiological mechanism of penile erection, and sildenafil can enhance the effect of NO, thus helping to relax smooth muscle, increase blood flow into the corpus cavernosum, make erection harder and maintain erection. In the absence of sexual stimulation, the recommended dose of sildenafil does not work. Therefore, sildenafil itself does not produce an erection, but only helps men to have a normal erection when they are sexually stimulated, and therefore does not usually affect the state of the penis after ejaculation. Normal men will trigger the weakening mechanism after ejaculation, so normal men taking sildenafil will also gradually weaken after ejaculation, and can also enter the erectile state again after sexual stimulation during the duration of the drug. Sildenafil has certain side effects, if necessary, it is recommended to carry out regular treatment under the guidance of a doctor, not self-medication, so as not to cause adverse consequences.