Viagra generally refers to the medication used to treat erectile dysfunction in men. Due to individual differences, there is no such thing as which medication is the best, and common medications include sildenafil citrate tablets, testosterone undecanoate gel pills, and phentolamine mesylate tablets. 1. Sildenafil citrate tablets: Sildenafil citrate tablets enhance the nitric oxide (NO)-cGMP pathway through selective inhibition of PDE5, elevating cGMP levels and leading to penile cavernous smooth muscle relaxation, so that patients with erectile dysfunction have a natural erectile response to sexual stimulation. The main adverse effects of this drug are headache, flushing, dizziness, and visual abnormalities. Its prohibited to combine with nitrate drugs, women, people who are allergic to this product, children, recent cardiovascular status should not have sex and other people prohibited this drug. 2. Testosterone undecanoate gel pills: After taking testosterone undecanoate gel pills, it can increase the level of testosterone in blood circulation, which can normalize the level of gonadotropins and relieve the effect of erectile dysfunction of the penis, which has a certain therapeutic effect on endocrine impotence. 3. Phentolamine mesylate tablets: its mechanism of action may be through the dilation of penile arterioles, so that its cavernous blood flow increases, thus improving penile erectile function, so that penile hardness increases, prolonged duration of erection. Adverse reactions such as nasal congestion, dizziness and chest tightness are common with this drug. It is contraindicated in people with low blood pressure, severe atherosclerosis, angina, as well as women, children, and people who are allergic to the product. If you want to know the drugs for treating erectile dysfunction in men, it is recommended to go to a regular hospital to consult a doctor and use the drug under the doctor’s guidance, and not to use the drug without authorization.