This study researched the birth control patch, Ortho Evra and the diffusivity of the hormones, ethinyl estradiol and norelogestromin, into the body through the epidermis. We modeled that all of the species that diffused through the epidermis was completely absorbed into the body. We found that our model validated the amounts given by Ortho Evra for drug release. However, many of the constraints and boundary conditions were taken from the Ortho Evra research information. Our study also analyzed the effectiveness of the hormone in women of varying weight, from 120 pounds to 198 pounds. Results indicated that the patch becomes less and less effective with increasing adipose tissue. This increase in adipose tissue results in a decreasing diffusivity value for the epidermis. Our study also researched the effects of incorrect usage of the Ortho Evra patch. We modeled the scenario of the patch falling off after a given time and the continued effectiveness of the drug. Our values imply that if the patch falls off the woman is not protected. The woman must restart the cycle in-order to reach steady state, which provides the needed amount of drug to be effective.