To practice vajroli mudra, engage the three bandhas (energy locks) while siting in padmasana or another comfortable seated pose. Constrict the muscles around the urethra, inhaling and exhaling up to 10 times. While constricting, focus on drawing energy up the spine and redirecting it to other chakras.
In addition to harnessing and redirecting sexual energy, the vajroli mudra is practiced by males to combat impotence or premature ejaculation. It is believed that with routine practice, semen can be redirected back into the body to cultivate and store sexual energy.
In a Tantric practice, withholding sexual energy from being released can cause the negative and positive poles of energy within an individual to unite in the body.