Tadalafil without a prescription can not be purchased privately, tadalafil belongs to the prescription drugs, must be prescribed by a doctor in the hospital or pharmacy to buy. Tadalafil belongs to a kind of PDE5 inhibitor, which has a certain therapeutic effect on male erectile dysfunction, and usually takes effect in about 30 minutes after taking it, and its effect usually lasts for more than 36 hours; during this period, as long as there are conditions of sexual stimulation, it can exert the effect of the drug, promote the blood flow of the penis, so as to improve the hardness of the erection. Some adverse reactions such as dizziness, headache, blurred vision and flushing may occur when taking tadalafil. Tadalafil is contraindicated in people who are allergic to any of the ingredients in the product, patients who are taking guanylate cyclase stimulators, women and children. In addition tadalafil should not be used in conjunction with any nitrate drugs, which can trigger postural hypotension, which in turn affects your health. When using medication, it is important to follow the doctor’s instructions, rational application of drugs, do not use drugs arbitrarily, to avoid causing adverse reactions.