Tadalafil works to treat erectile dysfunction. Tadalafil belongs to the type 5 phosphodiesterase inhibitors, the main effect is to selectively inhibit PDE5, enhance the nitric oxide (NO)-cGMP pathway, elevate the cGMP level and lead to the relaxation of penile cavernous smooth muscle, so that patients with erectile dysfunction to sexual stimulation to produce a natural erection, is the treatment of erectile dysfunction of the commonly used drugs. After taking it may produce headache, facial flushing, indigestion, nasal congestion and other adverse reactions; its and have nitrate drugs, such as nitroglycerin, etc., the joint use can produce intractable low blood pressure, belongs to the contraindications of the pairing, prohibit the joint use of the two. Tadalafil is also contraindicated in people who are allergic to any component of the product, patients taking guanylate cyclase stimulators, women, children and other groups. If patients need specific drugs, please purchase and use under the guidance of a physician or pharmacist.