Shendu and Xie Aili are both trade names for tadalafil, which are the same drug produced by different manufacturers and are not significantly different. Tadalafil selectively inhibits PDE5, enhances the nitric oxide (NO)-cGMP pathway, elevates cGMP levels and causes relaxation of penile cavernous smooth muscle, resulting in a natural erectile response to sexual stimulation in patients with erectile dysfunction. It is used clinically for the treatment of erectile dysfunction and the signs and symptoms of combined benign prostatic hyperplasia. Common adverse reactions to tadalafil include nasal congestion, limb pain, myalgia, headache, and dyspepsia; tadalafil is contraindicated in people who are allergic to any of the ingredients in the product, patients taking any form of nitrates, guanylate cyclase stimulators, women, children, and other people. It is recommended to consult a physician before using the drug and take the drug according to the doctor’s instructions, and should not be used blindly.