Minoxidil should be applied as 1 ml of solution or half a capful of foam to dry hair and scalp once in the morning and again in the evening. It should be spread evenly over the affected areas, and then the hands should be washed with warm water (if the hands are used for application). Minoxidil must be applied on the scalp at least twice daily and for at least four months to see results. Minoxidil works less well in patients that are older, have larger areas of baldness, and have been bald for longer periods of time. Minoxidil should be applied to a dry scalp only, and left in place for at least four hours. Minoxidil must be continued in order to maintain or increase the hair growth achieved.