Sildenafil citrate, which is used clinically to treat erectile dysfunction, is effective for up to 4 hours, with an average of 1-2 hours, how long it lasts needs to depend on whether the medication is effective and sexual intercourse to see, a few minutes to more than half an hour is possible.
Sildenafil needs to be taken before sex, 0.5 to 4 hours in advance can be, usually recommended to take 0.5-1 hours in advance, need to have sexual stimulation to work. Of course, due to the different physical condition of the individual, the absorption ability of the drug is different, the effective time will also be different, after taking the drug sexual life time from a few minutes to more than half an hour are possible.
Sildenafil citrate may have certain side effects, such as headache, dizziness and nausea. The drug is prohibited in combination with nitrates, it is contraindicated in women, people who are allergic to the product, children, people whose recent cardiovascular state does not allow them to have sex.
The appearance of erectile dysfunction, you need to go to the hospital for a relevant examination, under the guidance of the doctor reasonable application of drugs.