Zhewitra 20 mg, which contains the active ingredient vardenafil, typically takes around 30 to 60 minutes to start working after it is taken orally. However, the onset of action can vary from person to person based on factors such as individual metabolism, food intake, and other medications being taken. It's important to note that Zhewitra 20 mg, like other PDE5 inhibitors, requires sexual stimulation to achieve an erection. The medication works by relaxing the blood vessels in the penis, allowing for increased blood flow, which helps in achieving and maintaining an erection during sexual activity. The effects of vardenafil Zhewitra 20 mg can last for approximately 4 to 5 hours. During this time, a man may be able to achieve erections with greater ease, provided sexual stimulation is present. It's worth mentioning that the medication does not increase sexual desire or libido, and it should not be taken more than once within a 24-hour period.