Tadalafil tablets and sildenafil tablets belong to the same kind of drugs, both have their own characteristics, it is difficult to compare with which is safer. Tadalafil tablets and sildenafil tablets are type 5 phosphodiesterase inhibitors, and the common adverse effects of the two drugs are facial flushing, headache, palpitations, blurred vision, myalgia, dizziness, dyspepsia, and so on, and the magnitude of the side effects is related to the patient’s physical condition, the amount of medication taken and other factors. Taking these two drugs need to be under the guidance of a doctor, do not increase the dosage or increase the frequency of medication without authorization, so as not to cause serious side effects. Tadalafil tablets have a long duration of efficacy, the half-life of the drug is 17 hours, and can last 24-36 hours, although the effect is slow, but the duration is long. Sildenafil has a faster onset of action, usually half an hour can appear obvious effect, but the drug half-life is relatively short, 4 hours, the effect of the drug can last 4-6 hours.