Sit in padma asana or sidhda asana or vajra asana and make the shape of your lips as if you are whistling. In this position, take deep breath through the mouth first and then exhale through the nose. Your eyesight should be focused on the tip of the nose while doing so.
Juice flows from some special kinds of glands of the body by the practice of this mudra. The practice of this mudra is helpful in keeping a person far from old age and in curing the diseases. this mudra improves the digestion system too.