On the therapeutic effect of ED drugs, not only patients are concerned about the issue, but also male experts are concerned about the current to clarify the four causes of failure of drug therapy ED: 1, incorrectly taken Studies show that the wrong medication accounted for 81% of patients, mainly in the consumption of high-fat food after taking the drug, immediately after taking the drug for sex, no effective stimulation, or just a few sexual attempts, etc.. Available data indicate that a high-fat diet reduces the rate of drug absorption, increasing the time to reach the maximum blood concentration by about 1 hour, while the maximum blood concentration decreases by an average of 18%. Under normal conditions, the onset of action of the three PDE5 inhibitor classes of drugs, respectively, is 0.8-1 hour for sildenafil, 2 hours for tadalafil, and 0.9 hours for vardenafil. So patients who have sex immediately after taking the medication or simply follow the half hour before sex may not be effective. It should also be pointed out that PDE5 inhibitors are not “aphrodisiacs” and will not have an effect on the central nervous system, much less improve libido, and must have sufficient sexual stimulation after taking the drug to be effective. 2, did not reach the effective therapeutic dose, including a single dose did not reach the effective therapeutic dose, as well as effective treatment after not adhere to the medication. ed treatment only in the repeated use of drugs to improve and consolidate the efficacy, “to do a monk hit the bell” of the medication habit is difficult to achieve satisfactory results. And in the clinical selection, some doctors have a great arbitrariness, resulting in patients are not clear which drugs are most suitable for themselves, so irregular medication, dose instability and other cases are common. 3. Failure to adhere to medication treatment A study of more than 3 years found that the rate of patients stopping treatment was 57%. In Japan, after analyzing 667 patients who were successfully treated for the first time, it was noted that 48% of the patients were treated intermittently during the 3-year follow-up period. At present, some clinical experts have proposed that ED patients with drugs should be long-term, fixed, not just when there is sex. 4, fake drugs A large number of data show that patients from the network or some other channels, at significantly lower prices to buy counterfeit PDE5 inhibitor drugs, and finally caused by taking the medication is not ideal, or even serious adverse reactions. 2008 year-end, the National College of Brain Neurology in Singapore reported that eight patients aged 26-73 years old, due to the use of illegal aphrodisiacs led to The patients had severe brain damage. The fake drugs they took were known to contain the diabetic drug glibenclamide. In addition, in 2008, a total of 209 people in Singapore suffered serious adverse drug reactions from taking illegal drugs, of which 10 lost their lives.