Penis enlargement with tadalafil is not useful because tadalafil itself does not have penis enlargement properties. Tadalafil is a medication used to treat erectile dysfunction and is administered both on-demand and daily. Taking the drug on demand means taking it before sex, which can make one’s erection occur normally in the presence of sexual stimulation; while taking the drug on a daily basis can improve erectile function. However, tadalafil itself does not enlarge the penis, but only improves erectile function. The application of tadalafil may cause headache, dyspepsia, back pain, myalgia, limb pain and other adverse reactions; tadalafil is contraindicated in people who are taking nitrate drugs, those who have been allergic to the drug, and those who are using guanylate cyclase stimulators; possible causes of erectile dysfunction should be evaluated before treatment with the drug to choose the appropriate treatment. Men who suffer from short penis and want to enlarge it should seek professional help and not abuse drugs.