Viagra generally refers to sildenafil citrate tablets and it is not possible to assert which drug is better than sildenafil citrate tablets without side effects. Sildenafil citrate tablets belong to the class of phosphodiesterase type 5 inhibitors and are indicated for the treatment of erectile dysfunction in men. Other phosphodiesterase type 5 inhibitors, such as vardenafil and tadalafil, work on a similar principle as sildenafil citrate tablets, and also belong to the first-line treatment of erectile dysfunction, and can be substituted for their treatment. However, it should be noted that there is no such thing as a drug without side effects, and the effect of the drug is not only related to the drug itself, but also related to the individual’s physical fitness, drug compliance, severity of the disease, and other therapeutic measures, so the specific efficacy and adverse reactions may have individual differences. Therefore, it is not possible to presume which drug is more effective and has fewer side effects than Sildenafil Citrate Tablets. It should also be noted that the above mentioned phosphodiesterase type 5 inhibitors are prohibited for those who are allergic to them, or those who are using nitrate drugs such as nitroglycerin, isosorbide mononitrate, and other nitrate drugs, and headache, blurred vision, and other adverse reactions may occur in the process of using the drug. And in addition to these drugs, androgenic preparations (such as testosterone undecanoate pills), spongy active drugs (such as prostaglandin) and other drugs can also be used to treat erectile dysfunction. Therefore, those who have been diagnosed with erectile dysfunction must choose the medication under the guidance of a doctor according to the actual situation of the individual, and must not blindly use the medication or increase or decrease the dosage of the medication on their own, in order to avoid the adverse consequences.