Thus, Brazil (2002), informs that the cellophanes I contend 21 drgeas must be initiated in the first day of bleed and to have pause of seven days; cellophane with 22 drgeas must also be initiated in the first day of bleed and to have only pause of six days; whereas the ones that are composed for 24 drgeas have beginning in day the same of already cited, however it will only have a referring pause the four days. Already the cellophanes that possess 28 drgeas are the only ones that even so they have the same day of beginning of its taking, will not have period of pause between the cellophanes. (BRAZIL, 2002). Mechanism of action the Mechanism of action of these drugs acts inhibiting the ovulao, that is, possessing anovulatria action, becoming muco cervical thick and in such a way making it difficult the ticket of the spermatozoa. Promoting still alterations in the characteristics physicist-chemistries of the endometrium, keeping it are of the conditions adjusted for the implantation of the blastcito, and intervening with the motilidade and the quality of the secretion to glandular tubria (BRAZIL, 2009). In summary the mechanism of action of the pill is the following one: after the normal menstruation, hipfise, small situated gland in the skull, through a hormone of course elaborated by it, called folculo stimulant (FSH) and also responsible for the increase of vulo, stimulate the ovariana ovulao. At this moment, the ovrio also produces a estrognio hormone called, whose action is to transform the mucosa, that internally coats the uterus in excellent environment for the egg to nestle itself. This hormone when it reaches certain to rasp, goes to act braking hipfise in the manufacture of the FSH and the brake on hipfise is bigger. The FSH will be diminished or even though suppressed, making with that the matureness does not occur to ovular e, as consequence, does not happen to the ovulao.