There are many reasons for men to have a hard erection, the most important being insufficient hormone level, deficiency of kidney qi and penile cavernous body filling dysfunction, which need to be clearly diagnosed by further examination, including blood sampling for androgen level and penile blood flow Doppler examination. If the androgen level is insufficient, you can take testosterone undecanoate pills orally, as well as drugs to supplement kidney qi, such as Wu Zi Yan Zong Wan and Jin Kui Kidney Qi Wan, which can effectively improve erectile hardness in 2-3 months of treatment. If the examination reveals that the penile cavernous body is dysfunctional, you can choose some medications, such as Panax ginseng tablets, thromboxane capsules, and Rhodiola capsules, and continue the treatment for 4-8 weeks, which can also effectively improve the erectile hardness. During the treatment period, you should eat more leeks, oysters and okra, which are also useful for improving the erectile function of men.